ath - Change the way the edma rxfifo is reset

[dragonfly.git] / sys / dev / netif / ath / ath / if_ath.c

/*-
 * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 */

#include <sys/cdefs.h>

/*
 * Driver for the Atheros Wireless LAN controller.
 *
 * This software is derived from work of Atsushi Onoe; his contribution
 * is greatly appreciated.
 */

#include "opt_inet.h"
#include "opt_ath.h"
/*
 * This is needed for register operations which are performed
 * by the driver - eg, calls to ath_hal_gettsf32().
 *
 * It's also required for any AH_DEBUG checks in here, eg the
 * module dependencies.
 */
#include "opt_ah.h"
#include "opt_wlan.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/callout.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kthread.h>
#include <sys/taskqueue.h>
#include <sys/priv.h>
#include <sys/module.h>
#include <sys/ktr.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_llc.h>
#include <net/ifq_var.h>

#include <netproto/802_11/ieee80211_var.h>
#include <netproto/802_11/ieee80211_regdomain.h>
#ifdef IEEE80211_SUPPORT_SUPERG
#include <netproto/802_11/ieee80211_superg.h>
#endif
#ifdef IEEE80211_SUPPORT_TDMA
#include <netproto/802_11/ieee80211_tdma.h>
#endif

#include <net/bpf.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif

#include <dev/netif/ath/ath/if_athvar.h>
#include <dev/netif/ath/ath_hal/ah_devid.h>             /* XXX for softled */
#include <dev/netif/ath/ath_hal/ah_diagcodes.h>

#include <dev/netif/ath/ath/if_ath_debug.h>
#include <dev/netif/ath/ath/if_ath_misc.h>
#include <dev/netif/ath/ath/if_ath_tsf.h>
#include <dev/netif/ath/ath/if_ath_tx.h>
#include <dev/netif/ath/ath/if_ath_sysctl.h>
#include <dev/netif/ath/ath/if_ath_led.h>
#include <dev/netif/ath/ath/if_ath_keycache.h>
#include <dev/netif/ath/ath/if_ath_rx.h>
#include <dev/netif/ath/ath/if_ath_rx_edma.h>
#include <dev/netif/ath/ath/if_ath_tx_edma.h>
#include <dev/netif/ath/ath/if_ath_beacon.h>
#include <dev/netif/ath/ath/if_ath_btcoex.h>
#include <dev/netif/ath/ath/if_ath_spectral.h>
#include <dev/netif/ath/ath/if_ath_lna_div.h>
#include <dev/netif/ath/ath/if_athdfs.h>

#ifdef ATH_TX99_DIAG
#include <dev/netif/ath/ath_tx99/ath_tx99.h>
#endif

#ifdef  ATH_DEBUG_ALQ
#include <dev/netif/ath/ath/if_ath_alq.h>
#endif

/*
 * Only enable this if you're working on PS-POLL support.
 */
#define ATH_SW_PSQ

#ifdef __DragonFly__
#define CURVNET_SET(name)
#define CURVNET_RESTORE()
#endif

/*
 * ATH_BCBUF determines the number of vap's that can transmit
 * beacons and also (currently) the number of vap's that can
 * have unique mac addresses/bssid.  When staggering beacons
 * 4 is probably a good max as otherwise the beacons become
 * very closely spaced and there is limited time for cab q traffic
 * to go out.  You can burst beacons instead but that is not good
 * for stations in power save and at some point you really want
 * another radio (and channel).
 *
 * The limit on the number of mac addresses is tied to our use of
 * the U/L bit and tracking addresses in a byte; it would be
 * worthwhile to allow more for applications like proxy sta.
 */
CTASSERT(ATH_BCBUF <= 8);

static struct ieee80211vap *ath_vap_create(struct ieee80211com *,
                    const char [IFNAMSIZ], int, enum ieee80211_opmode, int,
                    const uint8_t [IEEE80211_ADDR_LEN],
                    const uint8_t [IEEE80211_ADDR_LEN]);
static void     ath_vap_delete(struct ieee80211vap *);
static void     ath_init(void *);
static void     ath_stop_locked(struct ifnet *);
static void     ath_stop(struct ifnet *);
static int      ath_reset_vap(struct ieee80211vap *, u_long);
static int      ath_transmit(struct ifnet *ifp, struct mbuf *m);
#if 0
static void     ath_qflush(struct ifnet *ifp);
#endif
static int      ath_media_change(struct ifnet *);
static void     ath_watchdog(void *);
static void     ath_start(struct ifnet *, struct ifaltq_subque *);
static int      ath_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
static void     ath_fatal_proc(void *, int);
static void     ath_bmiss_vap(struct ieee80211vap *);
static void     ath_bmiss_proc(void *, int);
static void     ath_key_update_begin(struct ieee80211vap *);
static void     ath_key_update_end(struct ieee80211vap *);
static void     ath_update_mcast(struct ifnet *);
static void     ath_update_promisc(struct ifnet *);
static void     ath_updateslot(struct ifnet *);
static void     ath_bstuck_proc(void *, int);
static void     ath_reset_proc(void *, int);
static int      ath_desc_alloc(struct ath_softc *);
static void     ath_desc_free(struct ath_softc *);
static struct ieee80211_node *ath_node_alloc(struct ieee80211vap *,
                        const uint8_t [IEEE80211_ADDR_LEN]);
static void     ath_node_cleanup(struct ieee80211_node *);
static void     ath_node_free(struct ieee80211_node *);
static void     ath_node_getsignal(const struct ieee80211_node *,
                        int8_t *, int8_t *);
static void     ath_txq_init(struct ath_softc *sc, struct ath_txq *, int);
static struct ath_txq *ath_txq_setup(struct ath_softc*, int qtype, int subtype);
static int      ath_tx_setup(struct ath_softc *, int, int);
static void     ath_tx_cleanupq(struct ath_softc *, struct ath_txq *);
static void     ath_tx_cleanup(struct ath_softc *);
static int      ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq,
                    int dosched);
static void     ath_tx_proc_q0(void *, int);
static void     ath_tx_proc_q0123(void *, int);
static void     ath_tx_proc(void *, int);
static void     ath_txq_sched_tasklet(void *, int);
static int      ath_chan_set(struct ath_softc *, struct ieee80211_channel *);
static void     ath_chan_change(struct ath_softc *, struct ieee80211_channel *);
static void     ath_scan_start(struct ieee80211com *);
static void     ath_scan_end(struct ieee80211com *);
static void     ath_set_channel(struct ieee80211com *);
#ifdef  ATH_ENABLE_11N
static void     ath_update_chw(struct ieee80211com *);
#endif  /* ATH_ENABLE_11N */
static void     ath_calibrate(void *);
static int      ath_newstate(struct ieee80211vap *, enum ieee80211_state, int);
static void     ath_setup_stationkey(struct ieee80211_node *);
static void     ath_newassoc(struct ieee80211_node *, int);
static int      ath_setregdomain(struct ieee80211com *,
                    struct ieee80211_regdomain *, int,
                    struct ieee80211_channel []);
static void     ath_getradiocaps(struct ieee80211com *, int, int *,
                    struct ieee80211_channel []);
static int      ath_getchannels(struct ath_softc *);

static int      ath_rate_setup(struct ath_softc *, u_int mode);
static void     ath_setcurmode(struct ath_softc *, enum ieee80211_phymode);

static void     ath_announce(struct ath_softc *);

static void     ath_dfs_tasklet(void *, int);
#if 0
static void     ath_node_powersave(struct ieee80211_node *, int);
static void     ath_node_recv_pspoll(struct ieee80211_node *, struct mbuf *);
#endif
static int      ath_node_set_tim(struct ieee80211_node *, int);

#ifdef IEEE80211_SUPPORT_TDMA
#include <dev/netif/ath/ath/if_ath_tdma.h>
#endif

extern  const char* ath_hal_ether_sprintf(const u_int8_t *mac);

SYSCTL_DECL(_hw_ath);

/* XXX validate sysctl values */
static  int ath_longcalinterval = 30;           /* long cals every 30 secs */
SYSCTL_INT(_hw_ath, OID_AUTO, longcal, CTLFLAG_RW, &ath_longcalinterval,
            0, "long chip calibration interval (secs)");
static  int ath_shortcalinterval = 100;         /* short cals every 100 ms */
SYSCTL_INT(_hw_ath, OID_AUTO, shortcal, CTLFLAG_RW, &ath_shortcalinterval,
            0, "short chip calibration interval (msecs)");
static  int ath_resetcalinterval = 20*60;       /* reset cal state 20 mins */
SYSCTL_INT(_hw_ath, OID_AUTO, resetcal, CTLFLAG_RW, &ath_resetcalinterval,
            0, "reset chip calibration results (secs)");
static  int ath_anicalinterval = 100;           /* ANI calibration - 100 msec */
SYSCTL_INT(_hw_ath, OID_AUTO, anical, CTLFLAG_RW, &ath_anicalinterval,
            0, "ANI calibration (msecs)");

int ath_rxbuf = ATH_RXBUF;              /* # rx buffers to allocate */
SYSCTL_INT(_hw_ath, OID_AUTO, rxbuf, CTLFLAG_RW, &ath_rxbuf,
            0, "rx buffers allocated");
TUNABLE_INT("hw.ath.rxbuf", &ath_rxbuf);
int ath_txbuf = ATH_TXBUF;              /* # tx buffers to allocate */
SYSCTL_INT(_hw_ath, OID_AUTO, txbuf, CTLFLAG_RW, &ath_txbuf,
            0, "tx buffers allocated");
TUNABLE_INT("hw.ath.txbuf", &ath_txbuf);
int ath_txbuf_mgmt = ATH_MGMT_TXBUF;    /* # mgmt tx buffers to allocate */
SYSCTL_INT(_hw_ath, OID_AUTO, txbuf_mgmt, CTLFLAG_RW, &ath_txbuf_mgmt,
            0, "tx (mgmt) buffers allocated");
TUNABLE_INT("hw.ath.txbuf_mgmt", &ath_txbuf_mgmt);

int ath_bstuck_threshold = 4;           /* max missed beacons */
SYSCTL_INT(_hw_ath, OID_AUTO, bstuck, CTLFLAG_RW, &ath_bstuck_threshold,
            0, "max missed beacon xmits before chip reset");

MALLOC_DEFINE(M_ATHDEV, "athdev", "ath driver dma buffers");

void
ath_legacy_attach_comp_func(struct ath_softc *sc)
{

        /*
         * Special case certain configurations.  Note the
         * CAB queue is handled by these specially so don't
         * include them when checking the txq setup mask.
         */
        switch (sc->sc_txqsetup &~ (1<<sc->sc_cabq->axq_qnum)) {
        case 0x01:
                TASK_INIT(&sc->sc_txtask, 0, ath_tx_proc_q0, sc);
                break;
        case 0x0f:
                TASK_INIT(&sc->sc_txtask, 0, ath_tx_proc_q0123, sc);
                break;
        default:
                TASK_INIT(&sc->sc_txtask, 0, ath_tx_proc, sc);
                break;
        }
}

/*
 * Set the target power mode.
 *
 * If this is called during a point in time where
 * the hardware is being programmed elsewhere, it will
 * simply store it away and update it when all current
 * uses of the hardware are completed.
 */
void
_ath_power_setpower(struct ath_softc *sc, int power_state, const char *file, int line)
{
        ATH_LOCK_ASSERT(sc);

        sc->sc_target_powerstate = power_state;

        DPRINTF(sc, ATH_DEBUG_PWRSAVE, "%s: (%s:%d) state=%d, refcnt=%d\n",
            __func__,
            file,
            line,
            power_state,
            sc->sc_powersave_refcnt);

        if (sc->sc_powersave_refcnt == 0 &&
            power_state != sc->sc_cur_powerstate) {
                sc->sc_cur_powerstate = power_state;
                ath_hal_setpower(sc->sc_ah, power_state);

                /*
                 * If the NIC is force-awake, then set the
                 * self-gen frame state appropriately.
                 *
                 * If the nic is in network sleep or full-sleep,
                 * we let the above call leave the self-gen
                 * state as "sleep".
                 */
                if (sc->sc_cur_powerstate == HAL_PM_AWAKE &&
                    sc->sc_target_selfgen_state != HAL_PM_AWAKE) {
                        ath_hal_setselfgenpower(sc->sc_ah,
                            sc->sc_target_selfgen_state);
                }
        }
}

/*
 * Set the current self-generated frames state.
 *
 * This is separate from the target power mode.  The chip may be
 * awake but the desired state is "sleep", so frames sent to the
 * destination has PWRMGT=1 in the 802.11 header.  The NIC also
 * needs to know to set PWRMGT=1 in self-generated frames.
 */
void
_ath_power_set_selfgen(struct ath_softc *sc, int power_state, const char *file, int line)
{

        ATH_LOCK_ASSERT(sc);

        DPRINTF(sc, ATH_DEBUG_PWRSAVE, "%s: (%s:%d) state=%d, refcnt=%d\n",
            __func__,
            file,
            line,
            power_state,
            sc->sc_target_selfgen_state);

        sc->sc_target_selfgen_state = power_state;

        /*
         * If the NIC is force-awake, then set the power state.
         * Network-state and full-sleep will already transition it to
         * mark self-gen frames as sleeping - and we can't
         * guarantee the NIC is awake to program the self-gen frame
         * setting anyway.
         */
        if (sc->sc_cur_powerstate == HAL_PM_AWAKE) {
                ath_hal_setselfgenpower(sc->sc_ah, power_state);
        }
}

/*
 * Set the hardware power mode and take a reference.
 *
 * This doesn't update the target power mode in the driver;
 * it just updates the hardware power state.
 *
 * XXX it should only ever force the hardware awake; it should
 * never be called to set it asleep.
 */
void
_ath_power_set_power_state(struct ath_softc *sc, int power_state, const char *file, int line)
{
        ATH_LOCK_ASSERT(sc);

        DPRINTF(sc, ATH_DEBUG_PWRSAVE, "%s: (%s:%d) state=%d, refcnt=%d\n",
            __func__,
            file,
            line,
            power_state,
            sc->sc_powersave_refcnt);

        sc->sc_powersave_refcnt++;

        if (power_state != sc->sc_cur_powerstate) {
                ath_hal_setpower(sc->sc_ah, power_state);
                sc->sc_cur_powerstate = power_state;

                /*
                 * Adjust the self-gen powerstate if appropriate.
                 */
                if (sc->sc_cur_powerstate == HAL_PM_AWAKE &&
                    sc->sc_target_selfgen_state != HAL_PM_AWAKE) {
                        ath_hal_setselfgenpower(sc->sc_ah,
                            sc->sc_target_selfgen_state);
                }

        }
}

/*
 * Restore the power save mode to what it once was.
 *
 * This will decrement the reference counter and once it hits
 * zero, it'll restore the powersave state.
 */
void
_ath_power_restore_power_state(struct ath_softc *sc, const char *file, int line)
{

        ATH_LOCK_ASSERT(sc);

        DPRINTF(sc, ATH_DEBUG_PWRSAVE, "%s: (%s:%d) refcnt=%d, target state=%d\n",
            __func__,
            file,
            line,
            sc->sc_powersave_refcnt,
            sc->sc_target_powerstate);

        if (sc->sc_powersave_refcnt == 0)
                device_printf(sc->sc_dev, "%s: refcnt=0?\n", __func__);
        else
                sc->sc_powersave_refcnt--;

        if (sc->sc_powersave_refcnt == 0 &&
            sc->sc_target_powerstate != sc->sc_cur_powerstate) {
                sc->sc_cur_powerstate = sc->sc_target_powerstate;
                ath_hal_setpower(sc->sc_ah, sc->sc_target_powerstate);
        }

        /*
         * Adjust the self-gen powerstate if appropriate.
         */
        if (sc->sc_cur_powerstate == HAL_PM_AWAKE &&
            sc->sc_target_selfgen_state != HAL_PM_AWAKE) {
                ath_hal_setselfgenpower(sc->sc_ah,
                    sc->sc_target_selfgen_state);
        }

}

#define HAL_MODE_HT20 (HAL_MODE_11NG_HT20 | HAL_MODE_11NA_HT20)
#define HAL_MODE_HT40 \
        (HAL_MODE_11NG_HT40PLUS | HAL_MODE_11NG_HT40MINUS | \
        HAL_MODE_11NA_HT40PLUS | HAL_MODE_11NA_HT40MINUS)
int
ath_attach(u_int16_t devid, struct ath_softc *sc)
{
        struct ifnet *ifp;
        struct ieee80211com *ic;
        struct ath_hal *ah = NULL;
        HAL_STATUS status;
        int error = 0, i;
        u_int wmodes;
        uint8_t macaddr[IEEE80211_ADDR_LEN];
        int rx_chainmask, tx_chainmask;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: devid 0x%x\n", __func__, devid);

        CURVNET_SET(vnet0);
        ifp = sc->sc_ifp = if_alloc(IFT_IEEE80211);
        if (ifp == NULL) {
                device_printf(sc->sc_dev, "can not if_alloc()\n");
                error = ENOSPC;
                CURVNET_RESTORE();
                goto bad;
        }
        ic = ifp->if_l2com;

        /* set these up early for if_printf use */
        if_initname(ifp, device_get_name(sc->sc_dev),
                device_get_unit(sc->sc_dev));
        CURVNET_RESTORE();

        sc->sc_rxfifo_state = ATH_RXFIFO_RESET;

        /* prepare sysctl tree for use in sub modules */
        sysctl_ctx_init(&sc->sc_sysctl_ctx);
        sc->sc_sysctl_tree = SYSCTL_ADD_NODE(&sc->sc_sysctl_ctx,
                SYSCTL_STATIC_CHILDREN(_hw),
                OID_AUTO,
                device_get_nameunit(sc->sc_dev),
                CTLFLAG_RD, 0, "");


        ah = ath_hal_attach(devid, sc, sc->sc_st, sc->sc_sh,
            sc->sc_eepromdata, &status);
        if (ah == NULL) {
                if_printf(ifp, "unable to attach hardware; HAL status %u\n",
                        status);
                error = ENXIO;
                goto bad;
        }
        sc->sc_ah = ah;
        sc->sc_invalid = 0;     /* ready to go, enable interrupt handling */
#ifdef  ATH_DEBUG
        sc->sc_debug = ath_debug;
#endif

        /*
         * Setup the DMA/EDMA functions based on the current
         * hardware support.
         *
         * This is required before the descriptors are allocated.
         */
        if (ath_hal_hasedma(sc->sc_ah)) {
                sc->sc_isedma = 1;
                ath_recv_setup_edma(sc);
                ath_xmit_setup_edma(sc);
        } else {
                ath_recv_setup_legacy(sc);
                ath_xmit_setup_legacy(sc);
        }

        if (ath_hal_hasmybeacon(sc->sc_ah)) {
                sc->sc_do_mybeacon = 1;
        }

        /*
         * Check if the MAC has multi-rate retry support.
         * We do this by trying to setup a fake extended
         * descriptor.  MAC's that don't have support will
         * return false w/o doing anything.  MAC's that do
         * support it will return true w/o doing anything.
         */
        sc->sc_mrretry = ath_hal_setupxtxdesc(ah, NULL, 0,0, 0,0, 0,0);

        /*
         * Check if the device has hardware counters for PHY
         * errors.  If so we need to enable the MIB interrupt
         * so we can act on stat triggers.
         */
        if (ath_hal_hwphycounters(ah))
                sc->sc_needmib = 1;

        /*
         * Get the hardware key cache size.
         */
        sc->sc_keymax = ath_hal_keycachesize(ah);
        if (sc->sc_keymax > ATH_KEYMAX) {
                if_printf(ifp, "Warning, using only %u of %u key cache slots\n",
                        ATH_KEYMAX, sc->sc_keymax);
                sc->sc_keymax = ATH_KEYMAX;
        }
        /*
         * Reset the key cache since some parts do not
         * reset the contents on initial power up.
         */
        for (i = 0; i < sc->sc_keymax; i++)
                ath_hal_keyreset(ah, i);

        /*
         * Collect the default channel list.
         */
        error = ath_getchannels(sc);
        if (error != 0)
                goto bad;

        /*
         * Setup rate tables for all potential media types.
         */
        ath_rate_setup(sc, IEEE80211_MODE_11A);
        ath_rate_setup(sc, IEEE80211_MODE_11B);
        ath_rate_setup(sc, IEEE80211_MODE_11G);
        ath_rate_setup(sc, IEEE80211_MODE_TURBO_A);
        ath_rate_setup(sc, IEEE80211_MODE_TURBO_G);
        ath_rate_setup(sc, IEEE80211_MODE_STURBO_A);
        ath_rate_setup(sc, IEEE80211_MODE_11NA);
        ath_rate_setup(sc, IEEE80211_MODE_11NG);
        ath_rate_setup(sc, IEEE80211_MODE_HALF);
        ath_rate_setup(sc, IEEE80211_MODE_QUARTER);

        /* NB: setup here so ath_rate_update is happy */
        ath_setcurmode(sc, IEEE80211_MODE_11A);

        /*
         * Allocate TX descriptors and populate the lists.
         */
        wlan_assert_serialized();
        wlan_serialize_exit();
        error = ath_desc_alloc(sc);
        wlan_serialize_enter();
        if (error != 0) {
                if_printf(ifp, "failed to allocate TX descriptors: %d\n",
                    error);
                goto bad;
        }
        error = ath_txdma_setup(sc);
        if (error != 0) {
                if_printf(ifp, "failed to allocate TX descriptors: %d\n",
                    error);
                goto bad;
        }

        /*
         * Allocate RX descriptors and populate the lists.
         */
        error = ath_rxdma_setup(sc);
        if (error != 0) {
                if_printf(ifp, "failed to allocate RX descriptors: %d\n",
                    error);
                goto bad;
        }

        callout_init_mp(&sc->sc_cal_ch);
        callout_init_mp(&sc->sc_wd_ch);

        ATH_TXBUF_LOCK_INIT(sc);

        sc->sc_tq = taskqueue_create("ath_taskq", M_INTWAIT,
                taskqueue_thread_enqueue, &sc->sc_tq);
        taskqueue_start_threads(&sc->sc_tq, 1, TDPRI_KERN_DAEMON, -1,
                "%s taskq", ifp->if_xname);

        TASK_INIT(&sc->sc_rxtask, 0, sc->sc_rx.recv_tasklet, sc);
        TASK_INIT(&sc->sc_bmisstask, 0, ath_bmiss_proc, sc);
        TASK_INIT(&sc->sc_bstucktask,0, ath_bstuck_proc, sc);
        TASK_INIT(&sc->sc_resettask,0, ath_reset_proc, sc);
        TASK_INIT(&sc->sc_txqtask, 0, ath_txq_sched_tasklet, sc);
        TASK_INIT(&sc->sc_fataltask, 0, ath_fatal_proc, sc);

        /*
         * Allocate hardware transmit queues: one queue for
         * beacon frames and one data queue for each QoS
         * priority.  Note that the hal handles resetting
         * these queues at the needed time.
         *
         * XXX PS-Poll
         */
        sc->sc_bhalq = ath_beaconq_setup(sc);
        if (sc->sc_bhalq == (u_int) -1) {
                if_printf(ifp, "unable to setup a beacon xmit queue!\n");
                error = EIO;
                goto bad2;
        }
        sc->sc_cabq = ath_txq_setup(sc, HAL_TX_QUEUE_CAB, 0);
        if (sc->sc_cabq == NULL) {
                if_printf(ifp, "unable to setup CAB xmit queue!\n");
                error = EIO;
                goto bad2;
        }
        /* NB: insure BK queue is the lowest priority h/w queue */
        if (!ath_tx_setup(sc, WME_AC_BK, HAL_WME_AC_BK)) {
                if_printf(ifp, "unable to setup xmit queue for %s traffic!\n",
                        ieee80211_wme_acnames[WME_AC_BK]);
                error = EIO;
                goto bad2;
        }
        if (!ath_tx_setup(sc, WME_AC_BE, HAL_WME_AC_BE) ||
            !ath_tx_setup(sc, WME_AC_VI, HAL_WME_AC_VI) ||
            !ath_tx_setup(sc, WME_AC_VO, HAL_WME_AC_VO)) {
                /*
                 * Not enough hardware tx queues to properly do WME;
                 * just punt and assign them all to the same h/w queue.
                 * We could do a better job of this if, for example,
                 * we allocate queues when we switch from station to
                 * AP mode.
                 */
                if (sc->sc_ac2q[WME_AC_VI] != NULL)
                        ath_tx_cleanupq(sc, sc->sc_ac2q[WME_AC_VI]);
                if (sc->sc_ac2q[WME_AC_BE] != NULL)
                        ath_tx_cleanupq(sc, sc->sc_ac2q[WME_AC_BE]);
                sc->sc_ac2q[WME_AC_BE] = sc->sc_ac2q[WME_AC_BK];
                sc->sc_ac2q[WME_AC_VI] = sc->sc_ac2q[WME_AC_BK];
                sc->sc_ac2q[WME_AC_VO] = sc->sc_ac2q[WME_AC_BK];
        }

        /*
         * Attach the TX completion function.
         *
         * The non-EDMA chips may have some special case optimisations;
         * this method gives everyone a chance to attach cleanly.
         */
        sc->sc_tx.xmit_attach_comp_func(sc);

        /*
         * Setup rate control.  Some rate control modules
         * call back to change the anntena state so expose
         * the necessary entry points.
         * XXX maybe belongs in struct ath_ratectrl?
         */
        sc->sc_setdefantenna = ath_setdefantenna;
        sc->sc_rc = ath_rate_attach(sc);
        if (sc->sc_rc == NULL) {
                error = EIO;
                goto bad2;
        }

        /* Attach DFS module */
        if (! ath_dfs_attach(sc)) {
                device_printf(sc->sc_dev,
                    "%s: unable to attach DFS\n", __func__);
                error = EIO;
                goto bad2;
        }

        /* Attach spectral module */
        if (ath_spectral_attach(sc) < 0) {
                device_printf(sc->sc_dev,
                    "%s: unable to attach spectral\n", __func__);
                error = EIO;
                goto bad2;
        }

        /* Attach bluetooth coexistence module */
        if (ath_btcoex_attach(sc) < 0) {
                device_printf(sc->sc_dev,
                    "%s: unable to attach bluetooth coexistence\n", __func__);
                error = EIO;
                goto bad2;
        }

        /* Attach LNA diversity module */
        if (ath_lna_div_attach(sc) < 0) {
                device_printf(sc->sc_dev,
                    "%s: unable to attach LNA diversity\n", __func__);
                error = EIO;
                goto bad2;
        }

        /* Start DFS processing tasklet */
        TASK_INIT(&sc->sc_dfstask, 0, ath_dfs_tasklet, sc);

        /* Configure LED state */
        sc->sc_blinking = 0;
        sc->sc_ledstate = 1;
        sc->sc_ledon = 0;                       /* low true */
        sc->sc_ledidle = (2700*hz)/1000;        /* 2.7sec */
        callout_init_mp(&sc->sc_ledtimer);

        /*
         * Don't setup hardware-based blinking.
         *
         * Although some NICs may have this configured in the
         * default reset register values, the user may wish
         * to alter which pins have which function.
         *
         * The reference driver attaches the MAC network LED to GPIO1 and
         * the MAC power LED to GPIO2.  However, the DWA-552 cardbus
         * NIC has these reversed.
         */
        sc->sc_hardled = (1 == 0);
        sc->sc_led_net_pin = -1;
        sc->sc_led_pwr_pin = -1;
        /*
         * Auto-enable soft led processing for IBM cards and for
         * 5211 minipci cards.  Users can also manually enable/disable
         * support with a sysctl.
         */
        sc->sc_softled = (devid == AR5212_DEVID_IBM || devid == AR5211_DEVID);
        ath_led_config(sc);
        ath_hal_setledstate(ah, HAL_LED_INIT);

        ifp->if_softc = sc;
        ifp->if_flags = IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST;
#if 0
        ifp->if_transmit = ath_transmit;
        ifp->if_qflush = ath_qflush;
#endif
        ifp->if_start = ath_start;
        ifp->if_ioctl = ath_ioctl;
        ifp->if_init = ath_init;
        ifq_set_maxlen(&ifp->if_snd, IFQ_MAXLEN);
#if 0
        ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
        IFQ_SET_READY(&ifp->if_snd);
#endif

        ic->ic_ifp = ifp;
        /* XXX not right but it's not used anywhere important */
        ic->ic_phytype = IEEE80211_T_OFDM;
        ic->ic_opmode = IEEE80211_M_STA;
        ic->ic_caps =
                  IEEE80211_C_STA               /* station mode */
                | IEEE80211_C_IBSS              /* ibss, nee adhoc, mode */
                | IEEE80211_C_HOSTAP            /* hostap mode */
                | IEEE80211_C_MONITOR           /* monitor mode */
                | IEEE80211_C_AHDEMO            /* adhoc demo mode */
                | IEEE80211_C_WDS               /* 4-address traffic works */
                | IEEE80211_C_MBSS              /* mesh point link mode */
                | IEEE80211_C_SHPREAMBLE        /* short preamble supported */
                | IEEE80211_C_SHSLOT            /* short slot time supported */
                | IEEE80211_C_WPA               /* capable of WPA1+WPA2 */
#ifndef ATH_ENABLE_11N
                | IEEE80211_C_BGSCAN            /* capable of bg scanning */
#endif
                | IEEE80211_C_TXFRAG            /* handle tx frags */
#ifdef  ATH_ENABLE_DFS
                | IEEE80211_C_DFS               /* Enable radar detection */
#endif
                | IEEE80211_C_PMGT              /* Station side power mgmt */
                | IEEE80211_C_SWSLEEP
                ;
        /*
         * Query the hal to figure out h/w crypto support.
         */
        if (ath_hal_ciphersupported(ah, HAL_CIPHER_WEP))
                ic->ic_cryptocaps |= IEEE80211_CRYPTO_WEP;
        if (ath_hal_ciphersupported(ah, HAL_CIPHER_AES_OCB))
                ic->ic_cryptocaps |= IEEE80211_CRYPTO_AES_OCB;
        if (ath_hal_ciphersupported(ah, HAL_CIPHER_AES_CCM))
                ic->ic_cryptocaps |= IEEE80211_CRYPTO_AES_CCM;
        if (ath_hal_ciphersupported(ah, HAL_CIPHER_CKIP))
                ic->ic_cryptocaps |= IEEE80211_CRYPTO_CKIP;
        if (ath_hal_ciphersupported(ah, HAL_CIPHER_TKIP)) {
                ic->ic_cryptocaps |= IEEE80211_CRYPTO_TKIP;
                /*
                 * Check if h/w does the MIC and/or whether the
                 * separate key cache entries are required to
                 * handle both tx+rx MIC keys.
                 */
                if (ath_hal_ciphersupported(ah, HAL_CIPHER_MIC))
                        ic->ic_cryptocaps |= IEEE80211_CRYPTO_TKIPMIC;
                /*
                 * If the h/w supports storing tx+rx MIC keys
                 * in one cache slot automatically enable use.
                 */
                if (ath_hal_hastkipsplit(ah) ||
                    !ath_hal_settkipsplit(ah, AH_FALSE))
                        sc->sc_splitmic = 1;
                /*
                 * If the h/w can do TKIP MIC together with WME then
                 * we use it; otherwise we force the MIC to be done
                 * in software by the net80211 layer.
                 */
                if (ath_hal_haswmetkipmic(ah))
                        sc->sc_wmetkipmic = 1;
        }
        sc->sc_hasclrkey = ath_hal_ciphersupported(ah, HAL_CIPHER_CLR);
        /*
         * Check for multicast key search support.
         */
        if (ath_hal_hasmcastkeysearch(sc->sc_ah) &&
            !ath_hal_getmcastkeysearch(sc->sc_ah)) {
                ath_hal_setmcastkeysearch(sc->sc_ah, 1);
        }
        sc->sc_mcastkey = ath_hal_getmcastkeysearch(ah);
        /*
         * Mark key cache slots associated with global keys
         * as in use.  If we knew TKIP was not to be used we
         * could leave the +32, +64, and +32+64 slots free.
         */
        for (i = 0; i < IEEE80211_WEP_NKID; i++) {
                setbit(sc->sc_keymap, i);
                setbit(sc->sc_keymap, i+64);
                if (sc->sc_splitmic) {
                        setbit(sc->sc_keymap, i+32);
                        setbit(sc->sc_keymap, i+32+64);
                }
        }
        /*
         * TPC support can be done either with a global cap or
         * per-packet support.  The latter is not available on
         * all parts.  We're a bit pedantic here as all parts
         * support a global cap.
         */
        if (ath_hal_hastpc(ah) || ath_hal_hastxpowlimit(ah))
                ic->ic_caps |= IEEE80211_C_TXPMGT;

        /*
         * Mark WME capability only if we have sufficient
         * hardware queues to do proper priority scheduling.
         */
        if (sc->sc_ac2q[WME_AC_BE] != sc->sc_ac2q[WME_AC_BK])
                ic->ic_caps |= IEEE80211_C_WME;
        /*
         * Check for misc other capabilities.
         */
        if (ath_hal_hasbursting(ah))
                ic->ic_caps |= IEEE80211_C_BURST;
        sc->sc_hasbmask = ath_hal_hasbssidmask(ah);
        sc->sc_hasbmatch = ath_hal_hasbssidmatch(ah);
        sc->sc_hastsfadd = ath_hal_hastsfadjust(ah);
        sc->sc_rxslink = ath_hal_self_linked_final_rxdesc(ah);
        sc->sc_rxtsf32 = ath_hal_has_long_rxdesc_tsf(ah);
        sc->sc_hasenforcetxop = ath_hal_hasenforcetxop(ah);
        sc->sc_rx_lnamixer = ath_hal_hasrxlnamixer(ah);
        sc->sc_hasdivcomb = ath_hal_hasdivantcomb(ah);

        if (ath_hal_hasfastframes(ah))
                ic->ic_caps |= IEEE80211_C_FF;
        wmodes = ath_hal_getwirelessmodes(ah);
        if (wmodes & (HAL_MODE_108G|HAL_MODE_TURBO))
                ic->ic_caps |= IEEE80211_C_TURBOP;
#ifdef IEEE80211_SUPPORT_TDMA
        if (ath_hal_macversion(ah) > 0x78) {
                ic->ic_caps |= IEEE80211_C_TDMA; /* capable of TDMA */
                ic->ic_tdma_update = ath_tdma_update;
        }
#endif

        /*
         * TODO: enforce that at least this many frames are available
         * in the txbuf list before allowing data frames (raw or
         * otherwise) to be transmitted.
         */
        sc->sc_txq_data_minfree = 10;
        /*
         * Leave this as default to maintain legacy behaviour.
         * Shortening the cabq/mcastq may end up causing some
         * undesirable behaviour.
         */
        sc->sc_txq_mcastq_maxdepth = ath_txbuf;

        /*
         * How deep can the node software TX queue get whilst it's asleep.
         */
        sc->sc_txq_node_psq_maxdepth = 16;

        /*
         * Default the maximum queue depth for a given node
         * to 1/4'th the TX buffers, or 64, whichever
         * is larger.
         */
        sc->sc_txq_node_maxdepth = MAX(64, ath_txbuf / 4);

        /* Enable CABQ by default */
        sc->sc_cabq_enable = 1;

        /*
         * Allow the TX and RX chainmasks to be overridden by
         * environment variables and/or device.hints.
         *
         * This must be done early - before the hardware is
         * calibrated or before the 802.11n stream calculation
         * is done.
         */
        if (resource_int_value(device_get_name(sc->sc_dev),
            device_get_unit(sc->sc_dev), "rx_chainmask",
            &rx_chainmask) == 0) {
                device_printf(sc->sc_dev, "Setting RX chainmask to 0x%x\n",
                    rx_chainmask);
                (void) ath_hal_setrxchainmask(sc->sc_ah, rx_chainmask);
        }
        if (resource_int_value(device_get_name(sc->sc_dev),
            device_get_unit(sc->sc_dev), "tx_chainmask",
            &tx_chainmask) == 0) {
                device_printf(sc->sc_dev, "Setting TX chainmask to 0x%x\n",
                    tx_chainmask);
                (void) ath_hal_settxchainmask(sc->sc_ah, tx_chainmask);
        }

        /*
         * Query the TX/RX chainmask configuration.
         *
         * This is only relevant for 11n devices.
         */
        ath_hal_getrxchainmask(ah, &sc->sc_rxchainmask);
        ath_hal_gettxchainmask(ah, &sc->sc_txchainmask);

        /*
         * Disable MRR with protected frames by default.
         * Only 802.11n series NICs can handle this.
         */
        sc->sc_mrrprot = 0;     /* XXX should be a capability */

        /*
         * Query the enterprise mode information the HAL.
         */
        if (ath_hal_getcapability(ah, HAL_CAP_ENTERPRISE_MODE, 0,
            &sc->sc_ent_cfg) == HAL_OK)
                sc->sc_use_ent = 1;

#ifdef  ATH_ENABLE_11N
        /*
         * Query HT capabilities
         */
        if (ath_hal_getcapability(ah, HAL_CAP_HT, 0, NULL) == HAL_OK &&
            (wmodes & (HAL_MODE_HT20 | HAL_MODE_HT40))) {
                uint32_t rxs, txs;

                device_printf(sc->sc_dev, "[HT] enabling HT modes\n");

                sc->sc_mrrprot = 1;     /* XXX should be a capability */

                ic->ic_htcaps = IEEE80211_HTC_HT        /* HT operation */
                            | IEEE80211_HTC_AMPDU       /* A-MPDU tx/rx */
                            | IEEE80211_HTC_AMSDU       /* A-MSDU tx/rx */
                            | IEEE80211_HTCAP_MAXAMSDU_3839
                                                        /* max A-MSDU length */
                            | IEEE80211_HTCAP_SMPS_OFF; /* SM power save off */

                /*
                 * Enable short-GI for HT20 only if the hardware
                 * advertises support.
                 * Notably, anything earlier than the AR9287 doesn't.
                 */
                if ((ath_hal_getcapability(ah,
                    HAL_CAP_HT20_SGI, 0, NULL) == HAL_OK) &&
                    (wmodes & HAL_MODE_HT20)) {
                        device_printf(sc->sc_dev,
                            "[HT] enabling short-GI in 20MHz mode\n");
                        ic->ic_htcaps |= IEEE80211_HTCAP_SHORTGI20;
                }

                if (wmodes & HAL_MODE_HT40)
                        ic->ic_htcaps |= IEEE80211_HTCAP_CHWIDTH40
                            |  IEEE80211_HTCAP_SHORTGI40;

                /*
                 * TX/RX streams need to be taken into account when
                 * negotiating which MCS rates it'll receive and
                 * what MCS rates are available for TX.
                 */
                (void) ath_hal_getcapability(ah, HAL_CAP_STREAMS, 0, &txs);
                (void) ath_hal_getcapability(ah, HAL_CAP_STREAMS, 1, &rxs);
                ic->ic_txstream = txs;
                ic->ic_rxstream = rxs;

                /*
                 * Setup TX and RX STBC based on what the HAL allows and
                 * the currently configured chainmask set.
                 * Ie - don't enable STBC TX if only one chain is enabled.
                 * STBC RX is fine on a single RX chain; it just won't
                 * provide any real benefit.
                 */
                if (ath_hal_getcapability(ah, HAL_CAP_RX_STBC, 0,
                    NULL) == HAL_OK) {
                        sc->sc_rx_stbc = 1;
                        device_printf(sc->sc_dev,
                            "[HT] 1 stream STBC receive enabled\n");
                        ic->ic_htcaps |= IEEE80211_HTCAP_RXSTBC_1STREAM;
                }
                if (txs > 1 && ath_hal_getcapability(ah, HAL_CAP_TX_STBC, 0,
                    NULL) == HAL_OK) {
                        sc->sc_tx_stbc = 1;
                        device_printf(sc->sc_dev,
                            "[HT] 1 stream STBC transmit enabled\n");
                        ic->ic_htcaps |= IEEE80211_HTCAP_TXSTBC;
                }

                (void) ath_hal_getcapability(ah, HAL_CAP_RTS_AGGR_LIMIT, 1,
                    &sc->sc_rts_aggr_limit);
                if (sc->sc_rts_aggr_limit != (64 * 1024))
                        device_printf(sc->sc_dev,
                            "[HT] RTS aggregates limited to %d KiB\n",
                            sc->sc_rts_aggr_limit / 1024);

                device_printf(sc->sc_dev,
                    "[HT] %d RX streams; %d TX streams\n", rxs, txs);
        }
#endif

        /*
         * Initial aggregation settings.
         */
        sc->sc_hwq_limit_aggr = ATH_AGGR_MIN_QDEPTH;
        sc->sc_hwq_limit_nonaggr = ATH_NONAGGR_MIN_QDEPTH;
        sc->sc_tid_hwq_lo = ATH_AGGR_SCHED_LOW;
        sc->sc_tid_hwq_hi = ATH_AGGR_SCHED_HIGH;
        sc->sc_aggr_limit = ATH_AGGR_MAXSIZE;
        sc->sc_delim_min_pad = 0;

        /*
         * Check if the hardware requires PCI register serialisation.
         * Some of the Owl based MACs require this.
         */
        if (ncpus > 1 &&
            ath_hal_getcapability(ah, HAL_CAP_SERIALISE_WAR,
             0, NULL) == HAL_OK) {
                sc->sc_ah->ah_config.ah_serialise_reg_war = 1;
                device_printf(sc->sc_dev,
                    "Enabling register serialisation\n");
        }

        /*
         * Initialise the deferred completed RX buffer list.
         */
        TAILQ_INIT(&sc->sc_rx_rxlist[HAL_RX_QUEUE_HP]);
        TAILQ_INIT(&sc->sc_rx_rxlist[HAL_RX_QUEUE_LP]);

        /*
         * Indicate we need the 802.11 header padded to a
         * 32-bit boundary for 4-address and QoS frames.
         */
        ic->ic_flags |= IEEE80211_F_DATAPAD;

        /*
         * Query the hal about antenna support.
         */
        sc->sc_defant = ath_hal_getdefantenna(ah);

        /*
         * Not all chips have the VEOL support we want to
         * use with IBSS beacons; check here for it.
         */
        sc->sc_hasveol = ath_hal_hasveol(ah);

        /* get mac address from hardware */
        ath_hal_getmac(ah, macaddr);
        if (sc->sc_hasbmask)
                ath_hal_getbssidmask(ah, sc->sc_hwbssidmask);

        /* NB: used to size node table key mapping array */
        ic->ic_max_keyix = sc->sc_keymax;
        /* call MI attach routine. */
        ieee80211_ifattach(ic, macaddr);
        ic->ic_setregdomain = ath_setregdomain;
        ic->ic_getradiocaps = ath_getradiocaps;
        sc->sc_opmode = HAL_M_STA;

        /* override default methods */
        ic->ic_newassoc = ath_newassoc;
        ic->ic_updateslot = ath_updateslot;
        ic->ic_wme.wme_update = ath_wme_update;
        ic->ic_vap_create = ath_vap_create;
        ic->ic_vap_delete = ath_vap_delete;
        ic->ic_raw_xmit = ath_raw_xmit;
        ic->ic_update_mcast = ath_update_mcast;
        ic->ic_update_promisc = ath_update_promisc;
        ic->ic_node_alloc = ath_node_alloc;
        sc->sc_node_free = ic->ic_node_free;
        ic->ic_node_free = ath_node_free;
        sc->sc_node_cleanup = ic->ic_node_cleanup;
        ic->ic_node_cleanup = ath_node_cleanup;
        ic->ic_node_getsignal = ath_node_getsignal;
        ic->ic_scan_start = ath_scan_start;
        ic->ic_scan_end = ath_scan_end;
        ic->ic_set_channel = ath_set_channel;
#ifdef  ATH_ENABLE_11N
        /* 802.11n specific - but just override anyway */
        sc->sc_addba_request = ic->ic_addba_request;
        sc->sc_addba_response = ic->ic_addba_response;
        sc->sc_addba_stop = ic->ic_addba_stop;
        sc->sc_bar_response = ic->ic_bar_response;
        sc->sc_addba_response_timeout = ic->ic_addba_response_timeout;

        ic->ic_addba_request = ath_addba_request;
        ic->ic_addba_response = ath_addba_response;
        ic->ic_addba_response_timeout = ath_addba_response_timeout;
        ic->ic_addba_stop = ath_addba_stop;
        ic->ic_bar_response = ath_bar_response;

        ic->ic_update_chw = ath_update_chw;
#endif  /* ATH_ENABLE_11N */

#ifdef  ATH_ENABLE_RADIOTAP_VENDOR_EXT
        /*
         * There's one vendor bitmap entry in the RX radiotap
         * header; make sure that's taken into account.
         */
        ieee80211_radiotap_attachv(ic,
            &sc->sc_tx_th.wt_ihdr, sizeof(sc->sc_tx_th), 0,
                ATH_TX_RADIOTAP_PRESENT,
            &sc->sc_rx_th.wr_ihdr, sizeof(sc->sc_rx_th), 1,
                ATH_RX_RADIOTAP_PRESENT);
#else
        /*
         * No vendor bitmap/extensions are present.
         */
        ieee80211_radiotap_attach(ic,
            &sc->sc_tx_th.wt_ihdr, sizeof(sc->sc_tx_th),
                ATH_TX_RADIOTAP_PRESENT,
            &sc->sc_rx_th.wr_ihdr, sizeof(sc->sc_rx_th),
                ATH_RX_RADIOTAP_PRESENT);
#endif  /* ATH_ENABLE_RADIOTAP_VENDOR_EXT */

        /*
         * Setup the ALQ logging if required
         */
#ifdef  ATH_DEBUG_ALQ
        if_ath_alq_init(&sc->sc_alq, device_get_nameunit(sc->sc_dev));
        if_ath_alq_setcfg(&sc->sc_alq,
            sc->sc_ah->ah_macVersion,
            sc->sc_ah->ah_macRev,
            sc->sc_ah->ah_phyRev,
            sc->sc_ah->ah_magic);
#endif

        /*
         * Setup dynamic sysctl's now that country code and
         * regdomain are available from the hal.
         */
        ath_sysctlattach(sc);
        ath_sysctl_stats_attach(sc);
        ath_sysctl_hal_attach(sc);

        if (bootverbose)
                ieee80211_announce(ic);
        ath_announce(sc);

        /*
         * Put it to sleep for now.
         */
        ath_power_setpower(sc, HAL_PM_FULL_SLEEP);

        return 0;
bad2:
        ath_tx_cleanup(sc);
        ath_desc_free(sc);
        ath_txdma_teardown(sc);
        ath_rxdma_teardown(sc);
bad:
        if (ah)
                ath_hal_detach(ah);

        /*
         * To work around scoping issues with CURVNET_SET/CURVNET_RESTORE..
         */
#if !defined(__DragonFly__)
        if (ifp != NULL && ifp->if_vnet) {
                CURVNET_SET(ifp->if_vnet);
                if_free(ifp);
                CURVNET_RESTORE();
        } else
#endif
        if (ifp != NULL)
                if_free(ifp);
        sc->sc_invalid = 1;
        return error;
}

int
ath_detach(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: if_flags %x\n",
                __func__, ifp->if_flags);

        /*
         * NB: the order of these is important:
         * o stop the chip so no more interrupts will fire
         * o call the 802.11 layer before detaching the hal to
         *   insure callbacks into the driver to delete global
         *   key cache entries can be handled
         * o free the taskqueue which drains any pending tasks
         * o reclaim the tx queue data structures after calling
         *   the 802.11 layer as we'll get called back to reclaim
         *   node state and potentially want to use them
         * o to cleanup the tx queues the hal is called, so detach
         *   it last
         * Other than that, it's straightforward...
         */

        /*
         * XXX Wake the hardware up first.  ath_stop() will still
         * wake it up first, but I'd rather do it here just to
         * ensure it's awake.
         */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        ath_power_setpower(sc, HAL_PM_AWAKE);

        /*
         * Stop things cleanly.
         */
        ath_stop(ifp);
        wlan_serialize_enter();
        ieee80211_ifdetach(ifp->if_l2com);
        wlan_serialize_exit();
        taskqueue_free(sc->sc_tq);
#ifdef ATH_TX99_DIAG
        if (sc->sc_tx99 != NULL)
                sc->sc_tx99->detach(sc->sc_tx99);
#endif
        ath_rate_detach(sc->sc_rc);
#ifdef  ATH_DEBUG_ALQ
        if_ath_alq_tidyup(&sc->sc_alq);
#endif
        ath_lna_div_detach(sc);
        ath_btcoex_detach(sc);
        ath_spectral_detach(sc);
        ath_dfs_detach(sc);
        ath_desc_free(sc);
        ath_txdma_teardown(sc);
        ath_rxdma_teardown(sc);
        ath_tx_cleanup(sc);
        ath_hal_detach(sc->sc_ah);      /* NB: sets chip in full sleep */

        CURVNET_SET(ifp->if_vnet);
        if_free(ifp);
        CURVNET_RESTORE();

        if (sc->sc_sysctl_tree) {
                sysctl_ctx_free(&sc->sc_sysctl_ctx);
                sc->sc_sysctl_tree = NULL;
        }

        return 0;
}

/*
 * MAC address handling for multiple BSS on the same radio.
 * The first vap uses the MAC address from the EEPROM.  For
 * subsequent vap's we set the U/L bit (bit 1) in the MAC
 * address and use the next six bits as an index.
 */
static void
assign_address(struct ath_softc *sc, uint8_t mac[IEEE80211_ADDR_LEN], int clone)
{
        int i;

        if (clone && sc->sc_hasbmask) {
                /* NB: we only do this if h/w supports multiple bssid */
                for (i = 0; i < 8; i++)
                        if ((sc->sc_bssidmask & (1<<i)) == 0)
                                break;
                if (i != 0)
                        mac[0] |= (i << 2)|0x2;
        } else
                i = 0;
        sc->sc_bssidmask |= 1<<i;
        sc->sc_hwbssidmask[0] &= ~mac[0];
        if (i == 0)
                sc->sc_nbssid0++;
}

static void
reclaim_address(struct ath_softc *sc, const uint8_t mac[IEEE80211_ADDR_LEN])
{
        int i = mac[0] >> 2;
        uint8_t mask;

        if (i != 0 || --sc->sc_nbssid0 == 0) {
                sc->sc_bssidmask &= ~(1<<i);
                /* recalculate bssid mask from remaining addresses */
                mask = 0xff;
                for (i = 1; i < 8; i++)
                        if (sc->sc_bssidmask & (1<<i))
                                mask &= ~((i<<2)|0x2);
                sc->sc_hwbssidmask[0] |= mask;
        }
}

/*
 * Assign a beacon xmit slot.  We try to space out
 * assignments so when beacons are staggered the
 * traffic coming out of the cab q has maximal time
 * to go out before the next beacon is scheduled.
 */
static int
assign_bslot(struct ath_softc *sc)
{
        u_int slot, free;

        free = 0;
        for (slot = 0; slot < ATH_BCBUF; slot++)
                if (sc->sc_bslot[slot] == NULL) {
                        if (sc->sc_bslot[(slot+1)%ATH_BCBUF] == NULL &&
                            sc->sc_bslot[(slot-1)%ATH_BCBUF] == NULL)
                                return slot;
                        free = slot;
                        /* NB: keep looking for a double slot */
                }
        return free;
}

static struct ieee80211vap *
ath_vap_create(struct ieee80211com *ic, const char name[IFNAMSIZ], int unit,
    enum ieee80211_opmode opmode, int flags,
    const uint8_t bssid[IEEE80211_ADDR_LEN],
    const uint8_t mac0[IEEE80211_ADDR_LEN])
{
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_vap *avp;
        struct ieee80211vap *vap;
        uint8_t mac[IEEE80211_ADDR_LEN];
        int needbeacon, error;
        enum ieee80211_opmode ic_opmode;

        avp = (struct ath_vap *) kmalloc(sizeof(struct ath_vap),
            M_80211_VAP, M_WAITOK | M_ZERO);
        needbeacon = 0;
        IEEE80211_ADDR_COPY(mac, mac0);

        ATH_LOCK(sc);
        ic_opmode = opmode;             /* default to opmode of new vap */
        switch (opmode) {
        case IEEE80211_M_STA:
                if (sc->sc_nstavaps != 0) {     /* XXX only 1 for now */
                        device_printf(sc->sc_dev, "only 1 sta vap supported\n");
                        goto bad;
                }
                if (sc->sc_nvaps) {
                        /*
                         * With multiple vaps we must fall back
                         * to s/w beacon miss handling.
                         */
                        flags |= IEEE80211_CLONE_NOBEACONS;
                }
                if (flags & IEEE80211_CLONE_NOBEACONS) {
                        /*
                         * Station mode w/o beacons are implemented w/ AP mode.
                         */
                        ic_opmode = IEEE80211_M_HOSTAP;
                }
                break;
        case IEEE80211_M_IBSS:
                if (sc->sc_nvaps != 0) {        /* XXX only 1 for now */
                        device_printf(sc->sc_dev,
                            "only 1 ibss vap supported\n");
                        goto bad;
                }
                needbeacon = 1;
                break;
        case IEEE80211_M_AHDEMO:
#ifdef IEEE80211_SUPPORT_TDMA
                if (flags & IEEE80211_CLONE_TDMA) {
                        if (sc->sc_nvaps != 0) {
                                device_printf(sc->sc_dev,
                                    "only 1 tdma vap supported\n");
                                goto bad;
                        }
                        needbeacon = 1;
                        flags |= IEEE80211_CLONE_NOBEACONS;
                }
                /* fall thru... */
#endif
        case IEEE80211_M_MONITOR:
                if (sc->sc_nvaps != 0 && ic->ic_opmode != opmode) {
                        /*
                         * Adopt existing mode.  Adding a monitor or ahdemo
                         * vap to an existing configuration is of dubious
                         * value but should be ok.
                         */
                        /* XXX not right for monitor mode */
                        ic_opmode = ic->ic_opmode;
                }
                break;
        case IEEE80211_M_HOSTAP:
        case IEEE80211_M_MBSS:
                needbeacon = 1;
                break;
        case IEEE80211_M_WDS:
                if (sc->sc_nvaps != 0 && ic->ic_opmode == IEEE80211_M_STA) {
                        device_printf(sc->sc_dev,
                            "wds not supported in sta mode\n");
                        goto bad;
                }
                /*
                 * Silently remove any request for a unique
                 * bssid; WDS vap's always share the local
                 * mac address.
                 */
                flags &= ~IEEE80211_CLONE_BSSID;
                if (sc->sc_nvaps == 0)
                        ic_opmode = IEEE80211_M_HOSTAP;
                else
                        ic_opmode = ic->ic_opmode;
                break;
        default:
                device_printf(sc->sc_dev, "unknown opmode %d\n", opmode);
                goto bad;
        }
        /*
         * Check that a beacon buffer is available; the code below assumes it.
         */
        if (needbeacon & TAILQ_EMPTY(&sc->sc_bbuf)) {
                device_printf(sc->sc_dev, "no beacon buffer available\n");
                goto bad;
        }

        /* STA, AHDEMO? */
        if (opmode == IEEE80211_M_HOSTAP || opmode == IEEE80211_M_MBSS) {
                assign_address(sc, mac, flags & IEEE80211_CLONE_BSSID);
                ath_hal_setbssidmask(sc->sc_ah, sc->sc_hwbssidmask);
        }

        vap = &avp->av_vap;
        /* XXX can't hold mutex across if_alloc */
        ATH_UNLOCK(sc);
        error = ieee80211_vap_setup(ic, vap, name, unit, opmode, flags,
            bssid, mac);
        ATH_LOCK(sc);
        if (error != 0) {
                device_printf(sc->sc_dev, "%s: error %d creating vap\n",
                    __func__, error);
                goto bad2;
        }

        /* h/w crypto support */
        vap->iv_key_alloc = ath_key_alloc;
        vap->iv_key_delete = ath_key_delete;
        vap->iv_key_set = ath_key_set;
        vap->iv_key_update_begin = ath_key_update_begin;
        vap->iv_key_update_end = ath_key_update_end;

        /* override various methods */
        avp->av_recv_mgmt = vap->iv_recv_mgmt;
        vap->iv_recv_mgmt = ath_recv_mgmt;
        vap->iv_reset = ath_reset_vap;
        vap->iv_update_beacon = ath_beacon_update;
        avp->av_newstate = vap->iv_newstate;
        vap->iv_newstate = ath_newstate;
        avp->av_bmiss = vap->iv_bmiss;
        vap->iv_bmiss = ath_bmiss_vap;

#if 0
        avp->av_node_ps = vap->iv_node_ps;
        vap->iv_node_ps = ath_node_powersave;
#endif

        avp->av_set_tim = vap->iv_set_tim;
        vap->iv_set_tim = ath_node_set_tim;

#if 0
        avp->av_recv_pspoll = vap->iv_recv_pspoll;
        vap->iv_recv_pspoll = ath_node_recv_pspoll;
#endif

        /* Set default parameters */

        /*
         * Anything earlier than some AR9300 series MACs don't
         * support a smaller MPDU density.
         */
        vap->iv_ampdu_density = IEEE80211_HTCAP_MPDUDENSITY_8;
        /*
         * All NICs can handle the maximum size, however
         * AR5416 based MACs can only TX aggregates w/ RTS
         * protection when the total aggregate size is <= 8k.
         * However, for now that's enforced by the TX path.
         */
        vap->iv_ampdu_rxmax = IEEE80211_HTCAP_MAXRXAMPDU_64K;

        avp->av_bslot = -1;
        if (needbeacon) {
                /*
                 * Allocate beacon state and setup the q for buffered
                 * multicast frames.  We know a beacon buffer is
                 * available because we checked above.
                 */
                avp->av_bcbuf = TAILQ_FIRST(&sc->sc_bbuf);
                TAILQ_REMOVE(&sc->sc_bbuf, avp->av_bcbuf, bf_list);
                if (opmode != IEEE80211_M_IBSS || !sc->sc_hasveol) {
                        /*
                         * Assign the vap to a beacon xmit slot.  As above
                         * this cannot fail to find a free one.
                         */
                        avp->av_bslot = assign_bslot(sc);
                        KASSERT(sc->sc_bslot[avp->av_bslot] == NULL,
                            ("beacon slot %u not empty", avp->av_bslot));
                        sc->sc_bslot[avp->av_bslot] = vap;
                        sc->sc_nbcnvaps++;
                }
                if (sc->sc_hastsfadd && sc->sc_nbcnvaps > 0) {
                        /*
                         * Multple vaps are to transmit beacons and we
                         * have h/w support for TSF adjusting; enable
                         * use of staggered beacons.
                         */
                        sc->sc_stagbeacons = 1;
                }
                ath_txq_init(sc, &avp->av_mcastq, ATH_TXQ_SWQ);
        }

        ic->ic_opmode = ic_opmode;
        if (opmode != IEEE80211_M_WDS) {
                sc->sc_nvaps++;
                if (opmode == IEEE80211_M_STA)
                        sc->sc_nstavaps++;
                if (opmode == IEEE80211_M_MBSS)
                        sc->sc_nmeshvaps++;
        }
        switch (ic_opmode) {
        case IEEE80211_M_IBSS:
                sc->sc_opmode = HAL_M_IBSS;
                break;
        case IEEE80211_M_STA:
                sc->sc_opmode = HAL_M_STA;
                break;
        case IEEE80211_M_AHDEMO:
#ifdef IEEE80211_SUPPORT_TDMA
                if (vap->iv_caps & IEEE80211_C_TDMA) {
                        sc->sc_tdma = 1;
                        /* NB: disable tsf adjust */
                        sc->sc_stagbeacons = 0;
                }
                /*
                 * NB: adhoc demo mode is a pseudo mode; to the hal it's
                 * just ap mode.
                 */
                /* fall thru... */
#endif
        case IEEE80211_M_HOSTAP:
        case IEEE80211_M_MBSS:
                sc->sc_opmode = HAL_M_HOSTAP;
                break;
        case IEEE80211_M_MONITOR:
                sc->sc_opmode = HAL_M_MONITOR;
                break;
        default:
                /* XXX should not happen */
                break;
        }
        if (sc->sc_hastsfadd) {
                /*
                 * Configure whether or not TSF adjust should be done.
                 */
                ath_hal_settsfadjust(sc->sc_ah, sc->sc_stagbeacons);
        }
        if (flags & IEEE80211_CLONE_NOBEACONS) {
                /*
                 * Enable s/w beacon miss handling.
                 */
                sc->sc_swbmiss = 1;
        }
        ATH_UNLOCK(sc);

        /* complete setup */
        ieee80211_vap_attach(vap, ath_media_change, ieee80211_media_status);
        return vap;
bad2:
        reclaim_address(sc, mac);
        ath_hal_setbssidmask(sc->sc_ah, sc->sc_hwbssidmask);
bad:
        kfree(avp, M_80211_VAP);
        ATH_UNLOCK(sc);
        return NULL;
}

static void
ath_vap_delete(struct ieee80211vap *vap)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ifnet *ifp = ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;
        struct ath_vap *avp = ATH_VAP(vap);

        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        DPRINTF(sc, ATH_DEBUG_RESET, "%s: called\n", __func__);
        if (ifp->if_flags & IFF_RUNNING) {
                /*
                 * Quiesce the hardware while we remove the vap.  In
                 * particular we need to reclaim all references to
                 * the vap state by any frames pending on the tx queues.
                 */
                ath_hal_intrset(ah, 0);         /* disable interrupts */
                ath_draintxq(sc, ATH_RESET_DEFAULT);            /* stop hw xmit side */
                /* XXX Do all frames from all vaps/nodes need draining here? */
                ath_stoprecv(sc, 1);            /* stop recv side */
        }

        /* .. leave the hardware awake for now. */

        ieee80211_vap_detach(vap);

        /*
         * XXX Danger Will Robinson! Danger!
         *
         * Because ieee80211_vap_detach() can queue a frame (the station
         * diassociate message?) after we've drained the TXQ and
         * flushed the software TXQ, we will end up with a frame queued
         * to a node whose vap is about to be freed.
         *
         * To work around this, flush the hardware/software again.
         * This may be racy - the ath task may be running and the packet
         * may be being scheduled between sw->hw txq. Tsk.
         *
         * TODO: figure out why a new node gets allocated somewhere around
         * here (after the ath_tx_swq() call; and after an ath_stop_locked()
         * call!)
         */

        ath_draintxq(sc, ATH_RESET_DEFAULT);

        ATH_LOCK(sc);
        /*
         * Reclaim beacon state.  Note this must be done before
         * the vap instance is reclaimed as we may have a reference
         * to it in the buffer for the beacon frame.
         */
        if (avp->av_bcbuf != NULL) {
                if (avp->av_bslot != -1) {
                        sc->sc_bslot[avp->av_bslot] = NULL;
                        sc->sc_nbcnvaps--;
                }
                ath_beacon_return(sc, avp->av_bcbuf);
                avp->av_bcbuf = NULL;
                if (sc->sc_nbcnvaps == 0) {
                        sc->sc_stagbeacons = 0;
                        if (sc->sc_hastsfadd)
                                ath_hal_settsfadjust(sc->sc_ah, 0);
                }
                /*
                 * Reclaim any pending mcast frames for the vap.
                 */
                ath_tx_draintxq(sc, &avp->av_mcastq);
        }
        /*
         * Update bookkeeping.
         */
        if (vap->iv_opmode == IEEE80211_M_STA) {
                sc->sc_nstavaps--;
                if (sc->sc_nstavaps == 0 && sc->sc_swbmiss)
                        sc->sc_swbmiss = 0;
        } else if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
            vap->iv_opmode == IEEE80211_M_MBSS) {
                reclaim_address(sc, vap->iv_myaddr);
                ath_hal_setbssidmask(ah, sc->sc_hwbssidmask);
                if (vap->iv_opmode == IEEE80211_M_MBSS)
                        sc->sc_nmeshvaps--;
        }
        if (vap->iv_opmode != IEEE80211_M_WDS)
                sc->sc_nvaps--;
#ifdef IEEE80211_SUPPORT_TDMA
        /* TDMA operation ceases when the last vap is destroyed */
        if (sc->sc_tdma && sc->sc_nvaps == 0) {
                sc->sc_tdma = 0;
                sc->sc_swbmiss = 0;
        }
#endif
        kfree(avp, M_80211_VAP);

        if (ifp->if_flags & IFF_RUNNING) {
                /*
                 * Restart rx+tx machines if still running (RUNNING will
                 * be reset if we just destroyed the last vap).
                 */
                if (ath_startrecv(sc) != 0)
                        if_printf(ifp, "%s: unable to restart recv logic\n",
                            __func__);
                if (sc->sc_beacons) {           /* restart beacons */
#ifdef IEEE80211_SUPPORT_TDMA
                        if (sc->sc_tdma)
                                ath_tdma_config(sc, NULL);
                        else
#endif
                                ath_beacon_config(sc, NULL);
                }
                ath_hal_intrset(ah, sc->sc_imask);
        }

        /* Ok, let the hardware asleep. */
        ath_power_restore_power_state(sc);
        ATH_UNLOCK(sc);
}

void
ath_suspend(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: if_flags %x\n",
                __func__, ifp->if_flags);

        sc->sc_resume_up = (ifp->if_flags & IFF_UP) != 0;

        ieee80211_suspend_all(ic);
        /*
         * NB: don't worry about putting the chip in low power
         * mode; pci will power off our socket on suspend and
         * CardBus detaches the device.
         */

        /*
         * XXX ensure none of the taskqueues are running
         * XXX ensure sc_invalid is 1
         * XXX ensure the calibration callout is disabled
         */

        /* Disable the PCIe PHY, complete with workarounds */
        ath_hal_enablepcie(sc->sc_ah, 1, 1);
}

/*
 * Reset the key cache since some parts do not reset the
 * contents on resume.  First we clear all entries, then
 * re-load keys that the 802.11 layer assumes are setup
 * in h/w.
 */
static void
ath_reset_keycache(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        int i;

        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        for (i = 0; i < sc->sc_keymax; i++)
                ath_hal_keyreset(ah, i);
        ath_power_restore_power_state(sc);
        ieee80211_crypto_reload_keys(ic);
}

/*
 * Fetch the current chainmask configuration based on the current
 * operating channel and options.
 */
static void
ath_update_chainmasks(struct ath_softc *sc, struct ieee80211_channel *chan)
{

        /*
         * Set TX chainmask to the currently configured chainmask;
         * the TX chainmask depends upon the current operating mode.
         */
        sc->sc_cur_rxchainmask = sc->sc_rxchainmask;
        if (IEEE80211_IS_CHAN_HT(chan)) {
                sc->sc_cur_txchainmask = sc->sc_txchainmask;
        } else {
                sc->sc_cur_txchainmask = 1;
        }

        DPRINTF(sc, ATH_DEBUG_RESET,
            "%s: TX chainmask is now 0x%x, RX is now 0x%x\n",
            __func__,
            sc->sc_cur_txchainmask,
            sc->sc_cur_rxchainmask);
}

void
ath_resume(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        HAL_STATUS status;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: if_flags %x\n",
                __func__, ifp->if_flags);

        /* Re-enable PCIe, re-enable the PCIe bus */
        ath_hal_enablepcie(ah, 0, 0);

        /*
         * Must reset the chip before we reload the
         * keycache as we were powered down on suspend.
         */
        ath_update_chainmasks(sc,
            sc->sc_curchan != NULL ? sc->sc_curchan : ic->ic_curchan);
        ath_hal_setchainmasks(sc->sc_ah, sc->sc_cur_txchainmask,
            sc->sc_cur_rxchainmask);

        /* Ensure we set the current power state to on */
        ath_power_setselfgen(sc, HAL_PM_AWAKE);
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        ath_power_setpower(sc, HAL_PM_AWAKE);

        sc->sc_rxfifo_state = ATH_RXFIFO_RESET;
        ath_hal_reset(ah, sc->sc_opmode,
            sc->sc_curchan != NULL ? sc->sc_curchan : ic->ic_curchan,
            AH_FALSE, &status);
        ath_reset_keycache(sc);

        /* Let DFS at it in case it's a DFS channel */
        ath_dfs_radar_enable(sc, ic->ic_curchan);

        /* Let spectral at in case spectral is enabled */
        ath_spectral_enable(sc, ic->ic_curchan);

        /*
         * Let bluetooth coexistence at in case it's needed for this channel
         */
        ath_btcoex_enable(sc, ic->ic_curchan);

        /*
         * If we're doing TDMA, enforce the TXOP limitation for chips that
         * support it.
         */
        if (sc->sc_hasenforcetxop && sc->sc_tdma)
                ath_hal_setenforcetxop(sc->sc_ah, 1);
        else
                ath_hal_setenforcetxop(sc->sc_ah, 0);

        /* Restore the LED configuration */
        ath_led_config(sc);
        ath_hal_setledstate(ah, HAL_LED_INIT);

        if (sc->sc_resume_up)
                ieee80211_resume_all(ic);

        ath_power_restore_power_state(sc);

        /* XXX beacons ? */
}

void
ath_shutdown(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: if_flags %x\n",
                __func__, ifp->if_flags);

        ath_stop(ifp);
        /* NB: no point powering down chip as we're about to reboot */
}

/*
 * Interrupt handler.  Most of the actual processing is deferred.
 */
void
ath_intr(void *arg)
{
        struct ath_softc *sc = arg;
        struct ifnet *ifp = sc->sc_ifp;
        struct ath_hal *ah = sc->sc_ah;
        HAL_INT status = 0;
        uint32_t txqs;

        /*
         * If we're inside a reset path, just print a warning and
         * clear the ISR. The reset routine will finish it for us.
         */
        ATH_PCU_LOCK(sc);
        if (sc->sc_inreset_cnt) {
                HAL_INT status;
                ath_hal_getisr(ah, &status);    /* clear ISR */
                ath_hal_intrset(ah, 0);         /* disable further intr's */
                DPRINTF(sc, ATH_DEBUG_ANY,
                    "%s: in reset, ignoring: status=0x%x\n",
                    __func__, status);
                ATH_PCU_UNLOCK(sc);
                return;
        }

        if (sc->sc_invalid) {
                /*
                 * The hardware is not ready/present, don't touch anything.
                 * Note this can happen early on if the IRQ is shared.
                 */
                DPRINTF(sc, ATH_DEBUG_ANY, "%s: invalid; ignored\n", __func__);
                ATH_PCU_UNLOCK(sc);
                return;
        }
        if (!ath_hal_intrpend(ah)) {            /* shared irq, not for us */
                ATH_PCU_UNLOCK(sc);
                return;
        }

        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        if ((ifp->if_flags & IFF_UP) == 0 ||
            (ifp->if_flags & IFF_RUNNING) == 0) {
                HAL_INT status;

                DPRINTF(sc, ATH_DEBUG_ANY, "%s: if_flags 0x%x\n",
                        __func__, ifp->if_flags);
                ath_hal_getisr(ah, &status);    /* clear ISR */
                ath_hal_intrset(ah, 0);         /* disable further intr's */
                ATH_PCU_UNLOCK(sc);
                ath_power_restore_power_state(sc);
                return;
        }

        /*
         * Figure out the reason(s) for the interrupt.  Note
         * that the hal returns a pseudo-ISR that may include
         * bits we haven't explicitly enabled so we mask the
         * value to insure we only process bits we requested.
         */
        ath_hal_getisr(ah, &status);            /* NB: clears ISR too */
        DPRINTF(sc, ATH_DEBUG_INTR, "%s: status 0x%x\n", __func__, status);
        ATH_KTR(sc, ATH_KTR_INTERRUPTS, 1, "ath_intr: mask=0x%.8x", status);
#ifdef  ATH_DEBUG_ALQ
        if_ath_alq_post_intr(&sc->sc_alq, status, ah->ah_intrstate,
            ah->ah_syncstate);
#endif  /* ATH_DEBUG_ALQ */
#ifdef  ATH_KTR_INTR_DEBUG
        ATH_KTR(sc, ATH_KTR_INTERRUPTS, 5,
            "ath_intr: ISR=0x%.8x, ISR_S0=0x%.8x, ISR_S1=0x%.8x, ISR_S2=0x%.8x, ISR_S5=0x%.8x",
            ah->ah_intrstate[0],
            ah->ah_intrstate[1],
            ah->ah_intrstate[2],
            ah->ah_intrstate[3],
            ah->ah_intrstate[6]);
#endif

        /* Squirrel away SYNC interrupt debugging */
        if (ah->ah_syncstate != 0) {
                int i;
                for (i = 0; i < 32; i++)
                        if (ah->ah_syncstate & (i << i))
                                sc->sc_intr_stats.sync_intr[i]++;
        }

        status &= sc->sc_imask;                 /* discard unasked for bits */

        /* Short-circuit un-handled interrupts */
        if (status == 0x0) {
                ATH_PCU_UNLOCK(sc);
                ath_power_restore_power_state(sc);
                return;
        }

        /*
         * Take a note that we're inside the interrupt handler, so
         * the reset routines know to wait.
         */
        sc->sc_intr_cnt++;
        ATH_PCU_UNLOCK(sc);

        /*
         * Handle the interrupt. We won't run concurrent with the reset
         * or channel change routines as they'll wait for sc_intr_cnt
         * to be 0 before continuing.
         */
        if (status & HAL_INT_FATAL) {
                sc->sc_stats.ast_hardware++;
                ath_hal_intrset(ah, 0);         /* disable intr's until reset */
                taskqueue_enqueue(sc->sc_tq, &sc->sc_fataltask);
        } else {
                if (status & HAL_INT_SWBA) {
                        /*
                         * Software beacon alert--time to send a beacon.
                         * Handle beacon transmission directly; deferring
                         * this is too slow to meet timing constraints
                         * under load.
                         */
#ifdef IEEE80211_SUPPORT_TDMA
                        if (sc->sc_tdma) {
                                if (sc->sc_tdmaswba == 0) {
                                        struct ieee80211com *ic = ifp->if_l2com;
                                        struct ieee80211vap *vap =
                                            TAILQ_FIRST(&ic->ic_vaps);
                                        ath_tdma_beacon_send(sc, vap);
                                        sc->sc_tdmaswba =
                                            vap->iv_tdma->tdma_bintval;
                                } else
                                        sc->sc_tdmaswba--;
                        } else
#endif
                        {
                                ath_beacon_proc(sc, 0);
#ifdef IEEE80211_SUPPORT_SUPERG
                                /*
                                 * Schedule the rx taskq in case there's no
                                 * traffic so any frames held on the staging
                                 * queue are aged and potentially flushed.
                                 */
                                sc->sc_rx.recv_sched(sc, 1);
#endif
                        }
                }
                if ((status & HAL_INT_RXEOL) && sc->sc_kickpcu == 0) {
                        int imask;
                        ATH_KTR(sc, ATH_KTR_ERROR, 0, "ath_intr: RXEOL");
                        ATH_PCU_LOCK(sc);
                        /*
                         * NB: the hardware should re-read the link when
                         *     RXE bit is written, but it doesn't work at
                         *     least on older hardware revs.
                         */
                        sc->sc_stats.ast_rxeol++;
                        /*
                         * Disable RXEOL/RXORN - prevent an interrupt
                         * storm until the PCU logic can be reset.
                         * In case the interface is reset some other
                         * way before "sc_kickpcu" is called, don't
                         * modify sc_imask - that way if it is reset
                         * by a call to ath_reset() somehow, the
                         * interrupt mask will be correctly reprogrammed.
                         */
                        imask = sc->sc_imask;
                        imask &= ~(HAL_INT_RXEOL | HAL_INT_RXORN);
                        ath_hal_intrset(ah, imask);
                        /*
                         * Only blank sc_rxlink if we've not yet kicked
                         * the PCU.
                         *
                         * This isn't entirely correct - the correct solution
                         * would be to have a PCU lock and engage that for
                         * the duration of the PCU fiddling; which would include
                         * running the RX process. Otherwise we could end up
                         * messing up the RX descriptor chain and making the
                         * RX desc list much shorter.
                         */
                        sc->sc_rxlink = NULL;
                        sc->sc_kickpcu = 1;
                        ATH_PCU_UNLOCK(sc);
                        /*
                         * Enqueue an RX proc, to handled whatever
                         * is in the RX queue.
                         * This will then kick the PCU.
                         */
                        sc->sc_rx.recv_sched(sc, 1);
                }
                if (status & HAL_INT_TXURN) {
                        sc->sc_stats.ast_txurn++;
                        /* bump tx trigger level */
                        ath_hal_updatetxtriglevel(ah, AH_TRUE);
                }
                /*
                 * Handle both the legacy and RX EDMA interrupt bits.
                 * Note that HAL_INT_RXLP is also HAL_INT_RXDESC.
                 */
                if (status & (HAL_INT_RX | HAL_INT_RXHP | HAL_INT_RXLP)) {
                        sc->sc_stats.ast_rx_intr++;
                        sc->sc_rx.recv_sched(sc, 1);
                }
                if (status & HAL_INT_TX) {
                        sc->sc_stats.ast_tx_intr++;
                        /*
                         * Grab all the currently set bits in the HAL txq bitmap
                         * and blank them. This is the only place we should be
                         * doing this.
                         */
                        if (! sc->sc_isedma) {
                                ATH_PCU_LOCK(sc);
                                txqs = 0xffffffff;
                                ath_hal_gettxintrtxqs(sc->sc_ah, &txqs);
                                ATH_KTR(sc, ATH_KTR_INTERRUPTS, 3,
                                    "ath_intr: TX; txqs=0x%08x, txq_active was 0x%08x, now 0x%08x",
                                    txqs,
                                    sc->sc_txq_active,
                                    sc->sc_txq_active | txqs);
                                sc->sc_txq_active |= txqs;
                                ATH_PCU_UNLOCK(sc);
                        }
                        taskqueue_enqueue(sc->sc_tq, &sc->sc_txtask);
                }
                if (status & HAL_INT_BMISS) {
                        sc->sc_stats.ast_bmiss++;
                        taskqueue_enqueue(sc->sc_tq, &sc->sc_bmisstask);
                }
                if (status & HAL_INT_GTT)
                        sc->sc_stats.ast_tx_timeout++;
                if (status & HAL_INT_CST)
                        sc->sc_stats.ast_tx_cst++;
                if (status & HAL_INT_MIB) {
                        sc->sc_stats.ast_mib++;
                        ATH_PCU_LOCK(sc);
                        /*
                         * Disable interrupts until we service the MIB
                         * interrupt; otherwise it will continue to fire.
                         */
                        ath_hal_intrset(ah, 0);
                        /*
                         * Let the hal handle the event.  We assume it will
                         * clear whatever condition caused the interrupt.
                         */
                        ath_hal_mibevent(ah, &sc->sc_halstats);
                        /*
                         * Don't reset the interrupt if we've just
                         * kicked the PCU, or we may get a nested
                         * RXEOL before the rxproc has had a chance
                         * to run.
                         */
                        if (sc->sc_kickpcu == 0)
                                ath_hal_intrset(ah, sc->sc_imask);
                        ATH_PCU_UNLOCK(sc);
                }
                if (status & HAL_INT_RXORN) {
                        /* NB: hal marks HAL_INT_FATAL when RXORN is fatal */
                        ATH_KTR(sc, ATH_KTR_ERROR, 0, "ath_intr: RXORN");
                        sc->sc_stats.ast_rxorn++;
                }
                if (status & HAL_INT_TSFOOR) {
                        device_printf(sc->sc_dev, "%s: TSFOOR\n", __func__);
                        sc->sc_syncbeacon = 1;
                }
        }
        ATH_PCU_LOCK(sc);
        sc->sc_intr_cnt--;
        ATH_PCU_UNLOCK(sc);

        ath_power_restore_power_state(sc);
}

static void
ath_fatal_proc(void *arg, int pending)
{
        struct ath_softc *sc = arg;
        struct ifnet *ifp = sc->sc_ifp;
        u_int32_t *state;
        u_int32_t len;
        void *sp;

        if_printf(ifp, "hardware error; resetting\n");
        /*
         * Fatal errors are unrecoverable.  Typically these
         * are caused by DMA errors.  Collect h/w state from
         * the hal so we can diagnose what's going on.
         */
        wlan_serialize_enter();
        if (ath_hal_getfatalstate(sc->sc_ah, &sp, &len)) {
                KASSERT(len >= 6*sizeof(u_int32_t), ("len %u bytes", len));
                state = sp;
                if_printf(ifp, "0x%08x 0x%08x 0x%08x, 0x%08x 0x%08x 0x%08x\n",
                    state[0], state[1] , state[2], state[3],
                    state[4], state[5]);
        }
        ath_reset(ifp, ATH_RESET_NOLOSS);
        wlan_serialize_exit();
}

static void
ath_bmiss_vap(struct ieee80211vap *vap)
{
        struct ath_softc *sc = vap->iv_ic->ic_ifp->if_softc;

        /*
         * Workaround phantom bmiss interrupts by sanity-checking
         * the time of our last rx'd frame.  If it is within the
         * beacon miss interval then ignore the interrupt.  If it's
         * truly a bmiss we'll get another interrupt soon and that'll
         * be dispatched up for processing.  Note this applies only
         * for h/w beacon miss events.
         */

        /*
         * XXX TODO: Just read the TSF during the interrupt path;
         * that way we don't have to wake up again just to read it
         * again.
         */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        if ((vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) == 0) {
                u_int64_t lastrx = sc->sc_lastrx;
                u_int64_t tsf = ath_hal_gettsf64(sc->sc_ah);
                /* XXX should take a locked ref to iv_bss */
                u_int bmisstimeout =
                        vap->iv_bmissthreshold * vap->iv_bss->ni_intval * 1024;

                DPRINTF(sc, ATH_DEBUG_BEACON,
                    "%s: tsf %llu lastrx %lld (%llu) bmiss %u\n",
                    __func__, (unsigned long long) tsf,
                    (unsigned long long)(tsf - lastrx),
                    (unsigned long long) lastrx, bmisstimeout);

                if (tsf - lastrx <= bmisstimeout) {
                        sc->sc_stats.ast_bmiss_phantom++;
                        ath_power_restore_power_state(sc);
                        return;
                }
        }

        /*
         * There's no need to keep the hardware awake during the call
         * to av_bmiss().
         */
        ath_power_restore_power_state(sc);

        /*
         * Attempt to force a beacon resync.
         */
        sc->sc_syncbeacon = 1;

        ATH_VAP(vap)->av_bmiss(vap);
}

/* XXX this needs a force wakeup! */
int
ath_hal_gethangstate(struct ath_hal *ah, uint32_t mask, uint32_t *hangs)
{
        uint32_t rsize;
        void *sp;

        if (!ath_hal_getdiagstate(ah, HAL_DIAG_CHECK_HANGS, &mask, sizeof(mask), &sp, &rsize))
                return 0;
        KASSERT(rsize == sizeof(uint32_t), ("resultsize %u", rsize));
        *hangs = *(uint32_t *)sp;
        return 1;
}

static void
ath_bmiss_proc(void *arg, int pending)
{
        struct ath_softc *sc = arg;
        struct ifnet *ifp = sc->sc_ifp;
        uint32_t hangs;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: pending %u\n", __func__, pending);

        /*
         * Do a reset upon any becaon miss event.
         *
         * It may be a non-recognised RX clear hang which needs a reset
         * to clear.
         */
        wlan_serialize_enter();
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        ath_beacon_miss(sc);
        if (ath_hal_gethangstate(sc->sc_ah, 0xff, &hangs) && hangs != 0) {
                ath_reset(ifp, ATH_RESET_NOLOSS);
                if_printf(ifp, "bb hang detected (0x%x), resetting\n", hangs);
        } else {
                ath_reset(ifp, ATH_RESET_NOLOSS);
                ieee80211_beacon_miss(ifp->if_l2com);
        }

        /* Force a beacon resync, in case they've drifted */
        sc->sc_syncbeacon = 1;
        ath_power_restore_power_state(sc);

        wlan_serialize_exit();
}

/*
 * Handle TKIP MIC setup to deal hardware that doesn't do MIC
 * calcs together with WME.  If necessary disable the crypto
 * hardware and mark the 802.11 state so keys will be setup
 * with the MIC work done in software.
 */
static void
ath_settkipmic(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;

        if ((ic->ic_cryptocaps & IEEE80211_CRYPTO_TKIP) && !sc->sc_wmetkipmic) {
                if (ic->ic_flags & IEEE80211_F_WME) {
                        ath_hal_settkipmic(sc->sc_ah, AH_FALSE);
                        ic->ic_cryptocaps &= ~IEEE80211_CRYPTO_TKIPMIC;
                } else {
                        ath_hal_settkipmic(sc->sc_ah, AH_TRUE);
                        ic->ic_cryptocaps |= IEEE80211_CRYPTO_TKIPMIC;
                }
        }
}

static void
ath_init(void *arg)
{
        struct ath_softc *sc = (struct ath_softc *) arg;
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        HAL_STATUS status;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: if_flags 0x%x\n",
                __func__, ifp->if_flags);

        ATH_LOCK(sc);
        /*
         * Stop anything previously setup.  This is safe
         * whether this is the first time through or not.
         */
        ath_stop_locked(ifp);

        /*
         * The basic interface to setting the hardware in a good
         * state is ``reset''.  On return the hardware is known to
         * be powered up and with interrupts disabled.  This must
         * be followed by initialization of the appropriate bits
         * and then setup of the interrupt mask.
         */
        ath_settkipmic(sc);
        ath_update_chainmasks(sc, ic->ic_curchan);
        ath_hal_setchainmasks(sc->sc_ah, sc->sc_cur_txchainmask,
            sc->sc_cur_rxchainmask);
        sc->sc_rxfifo_state = ATH_RXFIFO_RESET;
        if (!ath_hal_reset(ah, sc->sc_opmode, ic->ic_curchan, AH_FALSE, &status)) {
                if_printf(ifp, "unable to reset hardware; hal status %u\n",
                        status);
                ATH_UNLOCK(sc);
                return;
        }
        ath_chan_change(sc, ic->ic_curchan);

        /* Let DFS at it in case it's a DFS channel */
        ath_dfs_radar_enable(sc, ic->ic_curchan);

        /* Let spectral at in case spectral is enabled */
        ath_spectral_enable(sc, ic->ic_curchan);

        /*
         * Let bluetooth coexistence at in case it's needed for this channel
         */
        ath_btcoex_enable(sc, ic->ic_curchan);

        /*
         * If we're doing TDMA, enforce the TXOP limitation for chips that
         * support it.
         */
        if (sc->sc_hasenforcetxop && sc->sc_tdma)
                ath_hal_setenforcetxop(sc->sc_ah, 1);
        else
                ath_hal_setenforcetxop(sc->sc_ah, 0);

        /*
         * Likewise this is set during reset so update
         * state cached in the driver.
         */
        sc->sc_diversity = ath_hal_getdiversity(ah);
        sc->sc_lastlongcal = 0;
        sc->sc_resetcal = 1;
        sc->sc_lastcalreset = 0;
        sc->sc_lastani = 0;
        sc->sc_lastshortcal = 0;
        sc->sc_doresetcal = AH_FALSE;
        /*
         * Beacon timers were cleared here; give ath_newstate()
         * a hint that the beacon timers should be poked when
         * things transition to the RUN state.
         */
        sc->sc_beacons = 0;

        /*
         * Setup the hardware after reset: the key cache
         * is filled as needed and the receive engine is
         * set going.  Frame transmit is handled entirely
         * in the frame output path; there's nothing to do
         * here except setup the interrupt mask.
         */
        if (ath_startrecv(sc) != 0) {
                if_printf(ifp, "unable to start recv logic\n");
                ath_power_restore_power_state(sc);
                ATH_UNLOCK(sc);
                return;
        }

        /*
         * Enable interrupts.
         */
        sc->sc_imask = HAL_INT_RX | HAL_INT_TX
                  | HAL_INT_RXEOL | HAL_INT_RXORN
                  | HAL_INT_TXURN
                  | HAL_INT_FATAL | HAL_INT_GLOBAL;

        /*
         * Enable RX EDMA bits.  Note these overlap with
         * HAL_INT_RX and HAL_INT_RXDESC respectively.
         */
        if (sc->sc_isedma)
                sc->sc_imask |= (HAL_INT_RXHP | HAL_INT_RXLP);

        /*
         * Enable MIB interrupts when there are hardware phy counters.
         * Note we only do this (at the moment) for station mode.
         */
        if (sc->sc_needmib && ic->ic_opmode == IEEE80211_M_STA)
                sc->sc_imask |= HAL_INT_MIB;

        /*
         * XXX add capability for this.
         *
         * If we're in STA mode (and maybe IBSS?) then register for
         * TSFOOR interrupts.
         */
        if (ic->ic_opmode == IEEE80211_M_STA)
                sc->sc_imask |= HAL_INT_TSFOOR;

        /* Enable global TX timeout and carrier sense timeout if available */
        if (ath_hal_gtxto_supported(ah))
                sc->sc_imask |= HAL_INT_GTT;

        DPRINTF(sc, ATH_DEBUG_RESET, "%s: imask=0x%x\n",
                __func__, sc->sc_imask);

        ifp->if_flags |= IFF_RUNNING;
        callout_reset(&sc->sc_wd_ch, hz, ath_watchdog, sc);
        ath_hal_intrset(ah, sc->sc_imask);

        ath_power_restore_power_state(sc);
        ATH_UNLOCK(sc);

#ifdef ATH_TX99_DIAG
        if (sc->sc_tx99 != NULL)
                sc->sc_tx99->start(sc->sc_tx99);
        else
#endif
        ieee80211_start_all(ic);                /* start all vap's */
}

static void
ath_stop_locked(struct ifnet *ifp)
{
        struct ath_softc *sc = ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;

        DPRINTF(sc, ATH_DEBUG_ANY, "%s: invalid %u if_flags 0x%x\n",
                __func__, sc->sc_invalid, ifp->if_flags);

        ATH_LOCK_ASSERT(sc);

        /*
         * Wake the hardware up before fiddling with it.
         */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        if (ifp->if_flags & IFF_RUNNING) {
                /*
                 * Shutdown the hardware and driver:
                 *    reset 802.11 state machine
                 *    turn off timers
                 *    disable interrupts
                 *    turn off the radio
                 *    clear transmit machinery
                 *    clear receive machinery
                 *    drain and release tx queues
                 *    reclaim beacon resources
                 *    power down hardware
                 *
                 * Note that some of this work is not possible if the
                 * hardware is gone (invalid).
                 */
#ifdef ATH_TX99_DIAG
                if (sc->sc_tx99 != NULL)
                        sc->sc_tx99->stop(sc->sc_tx99);
#endif
                callout_stop(&sc->sc_wd_ch);
                sc->sc_wd_timer = 0;
                ifp->if_flags &= ~IFF_RUNNING;
                if (!sc->sc_invalid) {
                        if (sc->sc_softled) {
                                callout_stop(&sc->sc_ledtimer);
                                ath_hal_gpioset(ah, sc->sc_ledpin,
                                        !sc->sc_ledon);
                                sc->sc_blinking = 0;
                        }
                        ath_hal_intrset(ah, 0);
                }
                ath_draintxq(sc, ATH_RESET_DEFAULT);
                if (!sc->sc_invalid) {
                        ath_stoprecv(sc, 1);
                        ath_hal_phydisable(ah);
                } else
                        sc->sc_rxlink = NULL;
                ath_beacon_free(sc);    /* XXX not needed */
        }

        /* And now, restore the current power state */
        ath_power_restore_power_state(sc);
}

/*
 * Wait until all pending TX/RX has completed.
 *
 * This waits until all existing transmit, receive and interrupts
 * have completed.  It's assumed that the caller has first
 * grabbed the reset lock so it doesn't try to do overlapping
 * chip resets.
 */
#define MAX_TXRX_ITERATIONS     100
static void
ath_txrx_stop_locked(struct ath_softc *sc)
{
        int i = MAX_TXRX_ITERATIONS;

        ATH_UNLOCK_ASSERT(sc);
        ATH_PCU_LOCK_ASSERT(sc);

        /*
         * Sleep until all the pending operations have completed.
         *
         * The caller must ensure that reset has been incremented
         * or the pending operations may continue being queued.
         */
        while (sc->sc_rxproc_cnt || sc->sc_txproc_cnt ||
            sc->sc_txstart_cnt || sc->sc_intr_cnt) {
                if (i <= 0)
                        break;
                wlan_serialize_sleep(sc, 0, "ath_txrx_stop", (hz + 99) / 100);
                i--;
        }

        if (i <= 0)
                device_printf(sc->sc_dev,
                    "%s: didn't finish after %d iterations\n",
                    __func__, MAX_TXRX_ITERATIONS);
}
#undef  MAX_TXRX_ITERATIONS

#if 0
static void
ath_txrx_stop(struct ath_softc *sc)
{
        ATH_UNLOCK_ASSERT(sc);
        ATH_PCU_UNLOCK_ASSERT(sc);

        ATH_PCU_LOCK(sc);
        ath_txrx_stop_locked(sc);
        ATH_PCU_UNLOCK(sc);
}
#endif

static void
ath_txrx_start(struct ath_softc *sc)
{

        taskqueue_unblock(sc->sc_tq);
}

/*
 * Grab the reset lock, and wait around until noone else
 * is trying to do anything with it.
 *
 * This is totally horrible but we can't hold this lock for
 * long enough to do TX/RX or we end up with net80211/ip stack
 * LORs and eventual deadlock.
 *
 * "dowait" signals whether to spin, waiting for the reset
 * lock count to reach 0. This should (for now) only be used
 * during the reset path, as the rest of the code may not
 * be locking-reentrant enough to behave correctly.
 *
 * Another, cleaner way should be found to serialise all of
 * these operations.
 */
#define MAX_RESET_ITERATIONS    25
static int
ath_reset_grablock(struct ath_softc *sc, int dowait)
{
        int w = 0;
        int i = MAX_RESET_ITERATIONS;

        ATH_PCU_LOCK_ASSERT(sc);
        do {
                if (sc->sc_inreset_cnt == 0) {
                        w = 1;
                        break;
                }
                if (dowait == 0) {
                        w = 0;
                        break;
                }
                ATH_PCU_UNLOCK(sc);
                wlan_serialize_sleep(sc, 0, "ath_reset_grablock",
                                     (hz + 9) / 10);
                i--;
                ATH_PCU_LOCK(sc);
        } while (i > 0);

        /*
         * We always increment the refcounter, regardless
         * of whether we succeeded to get it in an exclusive
         * way.
         */
        sc->sc_inreset_cnt++;

        if (i <= 0)
                device_printf(sc->sc_dev,
                    "%s: didn't finish after %d iterations\n",
                    __func__, MAX_RESET_ITERATIONS);

        if (w == 0)
                device_printf(sc->sc_dev,
                    "%s: warning, recursive reset path!\n",
                    __func__);

        return w;
}
#undef MAX_RESET_ITERATIONS

/*
 * XXX TODO: write ath_reset_releaselock
 */

static void
ath_stop(struct ifnet *ifp)
{
        struct ath_softc *sc __unused = ifp->if_softc;

        ATH_LOCK(sc);
        ath_stop_locked(ifp);
        ATH_UNLOCK(sc);
}

/*
 * Reset the hardware w/o losing operational state.  This is
 * basically a more efficient way of doing ath_stop, ath_init,
 * followed by state transitions to the current 802.11
 * operational state.  Used to recover from various errors and
 * to reset or reload hardware state.
 */
int
ath_reset(struct ifnet *ifp, ATH_RESET_TYPE reset_type)
{
        struct ath_softc *sc = ifp->if_softc;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        HAL_STATUS status;
        int i;

        DPRINTF(sc, ATH_DEBUG_RESET, "%s: called\n", __func__);

        /* Ensure ATH_LOCK isn't held; ath_rx_proc can't be locked */
        ATH_PCU_UNLOCK_ASSERT(sc);
        ATH_UNLOCK_ASSERT(sc);

        /* Try to (stop any further TX/RX from occuring */
        taskqueue_block(sc->sc_tq);

        /*
         * Wake the hardware up.
         */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        ATH_PCU_LOCK(sc);

        /*
         * Grab the reset lock before TX/RX is stopped.
         *
         * This is needed to ensure that when the TX/RX actually does finish,
         * no further TX/RX/reset runs in parallel with this.
         */
        if (ath_reset_grablock(sc, 1) == 0) {
                device_printf(sc->sc_dev, "%s: concurrent reset! Danger!\n",
                    __func__);
        }

        /* disable interrupts */
        ath_hal_intrset(ah, 0);

        /*
         * Now, ensure that any in progress TX/RX completes before we
         * continue.
         */
        ath_txrx_stop_locked(sc);

        ATH_PCU_UNLOCK(sc);

        /*
         * Should now wait for pending TX/RX to complete
         * and block future ones from occuring. This needs to be
         * done before the TX queue is drained.
         */
        ath_draintxq(sc, reset_type);   /* stop xmit side */

        /*
         * Regardless of whether we're doing a no-loss flush or
         * not, stop the PCU and handle what's in the RX queue.
         * That way frames aren't dropped which shouldn't be.
         */
        ath_stoprecv(sc, (reset_type != ATH_RESET_NOLOSS));
        ath_rx_flush(sc);

        ath_settkipmic(sc);             /* configure TKIP MIC handling */
        /* NB: indicate channel change so we do a full reset */
        ath_update_chainmasks(sc, ic->ic_curchan);
        ath_hal_setchainmasks(sc->sc_ah, sc->sc_cur_txchainmask,
            sc->sc_cur_rxchainmask);
        sc->sc_rxfifo_state = ATH_RXFIFO_RESET;
        if (!ath_hal_reset(ah, sc->sc_opmode, ic->ic_curchan, AH_TRUE, &status))
                if_printf(ifp, "%s: unable to reset hardware; hal status %u\n",
                        __func__, status);
        sc->sc_diversity = ath_hal_getdiversity(ah);

        /* Let DFS at it in case it's a DFS channel */
        ath_dfs_radar_enable(sc, ic->ic_curchan);

        /* Let spectral at in case spectral is enabled */
        ath_spectral_enable(sc, ic->ic_curchan);

        /*
         * Let bluetooth coexistence at in case it's needed for this channel
         */
        ath_btcoex_enable(sc, ic->ic_curchan);

        /*
         * If we're doing TDMA, enforce the TXOP limitation for chips that
         * support it.
         */
        if (sc->sc_hasenforcetxop && sc->sc_tdma)
                ath_hal_setenforcetxop(sc->sc_ah, 1);
        else
                ath_hal_setenforcetxop(sc->sc_ah, 0);

        if (ath_startrecv(sc) != 0)     /* restart recv */
                if_printf(ifp, "%s: unable to start recv logic\n", __func__);
        /*
         * We may be doing a reset in response to an ioctl
         * that changes the channel so update any state that
         * might change as a result.
         */
        ath_chan_change(sc, ic->ic_curchan);
        if (sc->sc_beacons) {           /* restart beacons */
#ifdef IEEE80211_SUPPORT_TDMA
                if (sc->sc_tdma)
                        ath_tdma_config(sc, NULL);
                else
#endif
                        ath_beacon_config(sc, NULL);
        }

        /*
         * Release the reset lock and re-enable interrupts here.
         * If an interrupt was being processed in ath_intr(),
         * it would disable interrupts at this point. So we have
         * to atomically enable interrupts and decrement the
         * reset counter - this way ath_intr() doesn't end up
         * disabling interrupts without a corresponding enable
         * in the rest or channel change path.
         *
         * Grab the TX reference in case we need to transmit.
         * That way a parallel transmit doesn't.
         */
        ATH_PCU_LOCK(sc);
        sc->sc_inreset_cnt--;
        sc->sc_txstart_cnt++;
        /* XXX only do this if sc_inreset_cnt == 0? */
        ath_hal_intrset(ah, sc->sc_imask);
        ATH_PCU_UNLOCK(sc);

        /*
         * TX and RX can be started here. If it were started with
         * sc_inreset_cnt > 0, the TX and RX path would abort.
         * Thus if this is a nested call through the reset or
         * channel change code, TX completion will occur but
         * RX completion and ath_start / ath_tx_start will not
         * run.
         */

        /* XXX TODO: we need to hold the tx refcount here! */

        /* Restart TX/RX as needed */
        ath_txrx_start(sc);

        /* Restart TX completion and pending TX */
        if (reset_type == ATH_RESET_NOLOSS) {
                for (i = 0; i < HAL_NUM_TX_QUEUES; i++) {
                        if (ATH_TXQ_SETUP(sc, i)) {
                                ATH_TXQ_LOCK(&sc->sc_txq[i]);
                                ath_txq_restart_dma(sc, &sc->sc_txq[i]);
                                ATH_TXQ_UNLOCK(&sc->sc_txq[i]);

                                ATH_TX_LOCK(sc);
                                ath_txq_sched(sc, &sc->sc_txq[i]);
                                ATH_TX_UNLOCK(sc);
                        }
                }
        }

#if 0
        /* remove, DragonFly uses OACTIVE to control if_start calls */
        /*
         * This may have been set during an ath_start() call which
         * set this once it detected a concurrent TX was going on.
         * So, clear it.
         */
        IF_LOCK(&ifp->if_snd);
        ifq_clr_oactive(&ifp->if_snd);
        IF_UNLOCK(&ifp->if_snd);
#endif

        ath_power_restore_power_state(sc);

        ATH_PCU_LOCK(sc);
        sc->sc_txstart_cnt--;
        ATH_PCU_UNLOCK(sc);

        /* Handle any frames in the TX queue */
        /*
         * XXX should this be done by the caller, rather than
         * ath_reset() ?
         */
        ath_tx_kick(sc);                /* restart xmit */
        return 0;
}

static int
ath_reset_vap(struct ieee80211vap *vap, u_long cmd)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ifnet *ifp = ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;

        switch (cmd) {
        case IEEE80211_IOC_TXPOWER:
                /*
                 * If per-packet TPC is enabled, then we have nothing
                 * to do; otherwise we need to force the global limit.
                 * All this can happen directly; no need to reset.
                 */
                if (!ath_hal_gettpc(ah))
                        ath_hal_settxpowlimit(ah, ic->ic_txpowlimit);
                return 0;
        }
        /* XXX? Full or NOLOSS? */
        return ath_reset(ifp, ATH_RESET_FULL);
}

struct ath_buf *
_ath_getbuf_locked(struct ath_softc *sc, ath_buf_type_t btype)
{
        struct ath_buf *bf;

        ATH_TXBUF_LOCK_ASSERT(sc);

        if (btype == ATH_BUFTYPE_MGMT)
                bf = TAILQ_FIRST(&sc->sc_txbuf_mgmt);
        else
                bf = TAILQ_FIRST(&sc->sc_txbuf);

        if (bf == NULL) {
                sc->sc_stats.ast_tx_getnobuf++;
        } else {
                if (bf->bf_flags & ATH_BUF_BUSY) {
                        sc->sc_stats.ast_tx_getbusybuf++;
                        bf = NULL;
                }
        }

        if (bf != NULL && (bf->bf_flags & ATH_BUF_BUSY) == 0) {
                if (btype == ATH_BUFTYPE_MGMT)
                        TAILQ_REMOVE(&sc->sc_txbuf_mgmt, bf, bf_list);
                else {
                        TAILQ_REMOVE(&sc->sc_txbuf, bf, bf_list);
                        sc->sc_txbuf_cnt--;

                        /*
                         * This shuldn't happen; however just to be
                         * safe print a warning and fudge the txbuf
                         * count.
                         */
                        if (sc->sc_txbuf_cnt < 0) {
                                device_printf(sc->sc_dev,
                                    "%s: sc_txbuf_cnt < 0?\n",
                                    __func__);
                                sc->sc_txbuf_cnt = 0;
                        }
                }
        } else
                bf = NULL;

        if (bf == NULL) {
                /* XXX should check which list, mgmt or otherwise */
                DPRINTF(sc, ATH_DEBUG_XMIT, "%s: %s\n", __func__,
                    TAILQ_FIRST(&sc->sc_txbuf) == NULL ?
                        "out of xmit buffers" : "xmit buffer busy");
                return NULL;
        }

        /* XXX TODO: should do this at buffer list initialisation */
        /* XXX (then, ensure the buffer has the right flag set) */
        bf->bf_flags = 0;
        if (btype == ATH_BUFTYPE_MGMT)
                bf->bf_flags |= ATH_BUF_MGMT;
        else
                bf->bf_flags &= (~ATH_BUF_MGMT);

        /* Valid bf here; clear some basic fields */
        bf->bf_next = NULL;     /* XXX just to be sure */
        bf->bf_last = NULL;     /* XXX again, just to be sure */
        bf->bf_comp = NULL;     /* XXX again, just to be sure */
        bzero(&bf->bf_state, sizeof(bf->bf_state));

        /*
         * Track the descriptor ID only if doing EDMA
         */
        if (sc->sc_isedma) {
                bf->bf_descid = sc->sc_txbuf_descid;
                sc->sc_txbuf_descid++;
        }

        return bf;
}

/*
 * When retrying a software frame, buffers marked ATH_BUF_BUSY
 * can't be thrown back on the queue as they could still be
 * in use by the hardware.
 *
 * This duplicates the buffer, or returns NULL.
 *
 * The descriptor is also copied but the link pointers and
 * the DMA segments aren't copied; this frame should thus
 * be again passed through the descriptor setup/chain routines
 * so the link is correct.
 *
 * The caller must free the buffer using ath_freebuf().
 */
struct ath_buf *
ath_buf_clone(struct ath_softc *sc, struct ath_buf *bf)
{
        struct ath_buf *tbf;

        tbf = ath_getbuf(sc,
            (bf->bf_flags & ATH_BUF_MGMT) ?
             ATH_BUFTYPE_MGMT : ATH_BUFTYPE_NORMAL);
        if (tbf == NULL)
                return NULL;    /* XXX failure? Why? */

        /* Copy basics */
        tbf->bf_next = NULL;
        tbf->bf_nseg = bf->bf_nseg;
        tbf->bf_flags = bf->bf_flags & ATH_BUF_FLAGS_CLONE;
        tbf->bf_status = bf->bf_status;
        tbf->bf_m = bf->bf_m;
        tbf->bf_node = bf->bf_node;
        KASSERT((bf->bf_node != NULL), ("%s: bf_node=NULL!", __func__));
        /* will be setup by the chain/setup function */
        tbf->bf_lastds = NULL;
        /* for now, last == self */
        tbf->bf_last = tbf;
        tbf->bf_comp = bf->bf_comp;

        /* NOTE: DMA segments will be setup by the setup/chain functions */

        /* The caller has to re-init the descriptor + links */

        /*
         * Free the DMA mapping here, before we NULL the mbuf.
         * We must only call bus_dmamap_unload() once per mbuf chain
         * or behaviour is undefined.
         */
        if (bf->bf_m != NULL) {
                /*
                 * XXX is this POSTWRITE call required?
                 */
                bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
        }

        bf->bf_m = NULL;
        bf->bf_node = NULL;

        /* Copy state */
        memcpy(&tbf->bf_state, &bf->bf_state, sizeof(bf->bf_state));

        return tbf;
}

struct ath_buf *
ath_getbuf(struct ath_softc *sc, ath_buf_type_t btype)
{
        struct ath_buf *bf;

        ATH_TXBUF_LOCK(sc);
        bf = _ath_getbuf_locked(sc, btype);
        /*
         * If a mgmt buffer was requested but we're out of those,
         * try requesting a normal one.
         */
        if (bf == NULL && btype == ATH_BUFTYPE_MGMT)
                bf = _ath_getbuf_locked(sc, ATH_BUFTYPE_NORMAL);
        ATH_TXBUF_UNLOCK(sc);
        if (bf == NULL) {
#if 0
                struct ifnet *ifp = sc->sc_ifp;
#endif

                DPRINTF(sc, ATH_DEBUG_XMIT, "%s: stop queue\n", __func__);
                sc->sc_stats.ast_tx_qstop++;
#if 0
                /* remove, DragonFly uses OACTIVE to control if_start calls */
                IF_LOCK(&ifp->if_snd);
                ifq_set_oactive(&ifp->if_snd);
                IF_UNLOCK(&ifp->if_snd);
#endif
        }
        return bf;
}

#if 0

static void
ath_qflush(struct ifnet *ifp)
{

        /* XXX TODO */
}

#endif

/*
 * Transmit a single frame.
 *
 * net80211 will free the node reference if the transmit
 * fails, so don't free the node reference here.
 */
static int
ath_transmit(struct ifnet *ifp, struct mbuf *m)
{
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ieee80211_node *ni;
        struct mbuf *next;
        struct ath_buf *bf;
        ath_bufhead frags;
        int retval = 0;

        /*
         * Tell the reset path that we're currently transmitting.
         */
        ATH_PCU_LOCK(sc);
        if (sc->sc_inreset_cnt > 0) {
                DPRINTF(sc, ATH_DEBUG_XMIT,
                    "%s: sc_inreset_cnt > 0; bailing\n", __func__);
                ATH_PCU_UNLOCK(sc);
                IF_LOCK(&ifp->if_snd);
                sc->sc_stats.ast_tx_qstop++;
#if 0
                /* remove, DragonFly uses OACTIVE to control if_start calls */
                ifq_set_oactive(&ifp->if_snd);
#endif
                IF_UNLOCK(&ifp->if_snd);
                ATH_KTR(sc, ATH_KTR_TX, 0, "ath_start_task: OACTIVE, finish");
                m_freem(m);
                m = NULL;
                return (ENOBUFS);       /* XXX should be EINVAL or? */
        }
        sc->sc_txstart_cnt++;
        ATH_PCU_UNLOCK(sc);

        /* Wake the hardware up already */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        ATH_KTR(sc, ATH_KTR_TX, 0, "ath_transmit: start");
        /*
         * Grab the TX lock - it's ok to do this here; we haven't
         * yet started transmitting.
         */
        ATH_TX_LOCK(sc);

        /*
         * Node reference, if there's one.
         */
        ni = (struct ieee80211_node *) m->m_pkthdr.rcvif;

        /*
         * Enforce how deep a node queue can get.
         *
         * XXX it would be nicer if we kept an mbuf queue per
         * node and only whacked them into ath_bufs when we
         * are ready to schedule some traffic from them.
         * .. that may come later.
         *
         * XXX we should also track the per-node hardware queue
         * depth so it is easy to limit the _SUM_ of the swq and
         * hwq frames.  Since we only schedule two HWQ frames
         * at a time, this should be OK for now.
         */
        if ((!(m->m_flags & M_EAPOL)) &&
            (ATH_NODE(ni)->an_swq_depth > sc->sc_txq_node_maxdepth)) {
                sc->sc_stats.ast_tx_nodeq_overflow++;
                m_freem(m);
                m = NULL;
                retval = ENOBUFS;
                goto finish;
        }

        /*
         * Check how many TX buffers are available.
         *
         * If this is for non-EAPOL traffic, just leave some
         * space free in order for buffer cloning and raw
         * frame transmission to occur.
         *
         * If it's for EAPOL traffic, ignore this for now.
         * Management traffic will be sent via the raw transmit
         * method which bypasses this check.
         *
         * This is needed to ensure that EAPOL frames during
         * (re) keying have a chance to go out.
         *
         * See kern/138379 for more information.
         */
        if ((!(m->m_flags & M_EAPOL)) &&
            (sc->sc_txbuf_cnt <= sc->sc_txq_data_minfree)) {
                sc->sc_stats.ast_tx_nobuf++;
                m_freem(m);
                m = NULL;
                retval = ENOBUFS;
                goto finish;
        }

        /*
         * Grab a TX buffer and associated resources.
         *
         * If it's an EAPOL frame, allocate a MGMT ath_buf.
         * That way even with temporary buffer exhaustion due to
         * the data path doesn't leave us without the ability
         * to transmit management frames.
         *
         * Otherwise allocate a normal buffer.
         */
        if (m->m_flags & M_EAPOL)
                bf = ath_getbuf(sc, ATH_BUFTYPE_MGMT);
        else
                bf = ath_getbuf(sc, ATH_BUFTYPE_NORMAL);

        if (bf == NULL) {
                /*
                 * If we failed to allocate a buffer, fail.
                 *
                 * We shouldn't fail normally, due to the check
                 * above.
                 */
                sc->sc_stats.ast_tx_nobuf++;
#if 0
                /* remove, DragonFly uses OACTIVE to control if_start calls */
                IF_LOCK(&ifp->if_snd);
                ifq_set_oactive(&ifp->if_snd);
                IF_UNLOCK(&ifp->if_snd);
#endif
                m_freem(m);
                m = NULL;
                retval = ENOBUFS;
                goto finish;
        }

        /*
         * At this point we have a buffer; so we need to free it
         * if we hit any error conditions.
         */

        /*
         * Check for fragmentation.  If this frame
         * has been broken up verify we have enough
         * buffers to send all the fragments so all
         * go out or none...
         */
        TAILQ_INIT(&frags);
        if ((m->m_flags & M_FRAG) &&
            !ath_txfrag_setup(sc, &frags, m, ni)) {
                DPRINTF(sc, ATH_DEBUG_XMIT,
                    "%s: out of txfrag buffers\n", __func__);
                sc->sc_stats.ast_tx_nofrag++;
                ifp->if_oerrors++;
                ath_freetx(m);
                goto bad;
        }

        /*
         * At this point if we have any TX fragments, then we will
         * have bumped the node reference once for each of those.
         */

        /*
         * XXX Is there anything actually _enforcing_ that the
         * fragments are being transmitted in one hit, rather than
         * being interleaved with other transmissions on that
         * hardware queue?
         *
         * The ATH TX output lock is the only thing serialising this
         * right now.
         */

        /*
         * Calculate the "next fragment" length field in ath_buf
         * in order to let the transmit path know enough about
         * what to next write to the hardware.
         */
        if (m->m_flags & M_FRAG) {
                struct ath_buf *fbf = bf;
                struct ath_buf *n_fbf = NULL;
                struct mbuf *fm = m->m_nextpkt;

                /*
                 * We need to walk the list of fragments and set
                 * the next size to the following buffer.
                 * However, the first buffer isn't in the frag
                 * list, so we have to do some gymnastics here.
                 */
                TAILQ_FOREACH(n_fbf, &frags, bf_list) {
                        fbf->bf_nextfraglen = fm->m_pkthdr.len;
                        fbf = n_fbf;
                        fm = fm->m_nextpkt;
                }
        }

        /*
         * Bump the ifp output counter.
         *
         * XXX should use atomics?
         */
        ifp->if_opackets++;
nextfrag:
        /*
         * Pass the frame to the h/w for transmission.
         * Fragmented frames have each frag chained together
         * with m_nextpkt.  We know there are sufficient ath_buf's
         * to send all the frags because of work done by
         * ath_txfrag_setup.  We leave m_nextpkt set while
         * calling ath_tx_start so it can use it to extend the
         * the tx duration to cover the subsequent frag and
         * so it can reclaim all the mbufs in case of an error;
         * ath_tx_start clears m_nextpkt once it commits to
         * handing the frame to the hardware.
         *
         * Note: if this fails, then the mbufs are freed but
         * not the node reference.
         */
        next = m->m_nextpkt;
        if (ath_tx_start(sc, ni, bf, m)) {
bad:
                ifp->if_oerrors++;
reclaim:
                bf->bf_m = NULL;
                bf->bf_node = NULL;
                ATH_TXBUF_LOCK(sc);
                ath_returnbuf_head(sc, bf);
                /*
                 * Free the rest of the node references and
                 * buffers for the fragment list.
                 */
                ath_txfrag_cleanup(sc, &frags, ni);
                ATH_TXBUF_UNLOCK(sc);
                retval = ENOBUFS;
                goto finish;
        }

        /*
         * Check here if the node is in power save state.
         */
        ath_tx_update_tim(sc, ni, 1);

        if (next != NULL) {
                /*
                 * Beware of state changing between frags.
                 * XXX check sta power-save state?
                 */
                if (ni->ni_vap->iv_state != IEEE80211_S_RUN) {
                        DPRINTF(sc, ATH_DEBUG_XMIT,
                            "%s: flush fragmented packet, state %s\n",
                            __func__,
                            ieee80211_state_name[ni->ni_vap->iv_state]);
                        /* XXX dmamap */
                        ath_freetx(next);
                        goto reclaim;
                }
                m = next;
                bf = TAILQ_FIRST(&frags);
                KASSERT(bf != NULL, ("no buf for txfrag"));
                TAILQ_REMOVE(&frags, bf, bf_list);
                goto nextfrag;
        }

        /*
         * Bump watchdog timer.
         */
        sc->sc_wd_timer = 5;

finish:
        ATH_TX_UNLOCK(sc);

        /*
         * Finished transmitting!
         */
        ATH_PCU_LOCK(sc);
        sc->sc_txstart_cnt--;
        ATH_PCU_UNLOCK(sc);

        /* Sleep the hardware if required */
        ath_power_restore_power_state(sc);

        ATH_KTR(sc, ATH_KTR_TX, 0, "ath_transmit: finished");
        
        return (retval);
}

static int
ath_media_change(struct ifnet *ifp)
{
        int error = ieee80211_media_change(ifp);
        /* NB: only the fixed rate can change and that doesn't need a reset */
        return (error == ENETRESET ? 0 : error);
}

/*
 * Block/unblock tx+rx processing while a key change is done.
 * We assume the caller serializes key management operations
 * so we only need to worry about synchronization with other
 * uses that originate in the driver.
 */
static void
ath_key_update_begin(struct ieee80211vap *vap)
{
        struct ifnet *ifp = vap->iv_ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;

        DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s:\n", __func__);
        taskqueue_block(sc->sc_tq);
}

static void
ath_key_update_end(struct ieee80211vap *vap)
{
        struct ifnet *ifp = vap->iv_ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;

        DPRINTF(sc, ATH_DEBUG_KEYCACHE, "%s:\n", __func__);
        taskqueue_unblock(sc->sc_tq);
}

static void
ath_update_promisc(struct ifnet *ifp)
{
        struct ath_softc *sc = ifp->if_softc;
        u_int32_t rfilt;

        /* configure rx filter */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        rfilt = ath_calcrxfilter(sc);
        ath_hal_setrxfilter(sc->sc_ah, rfilt);
        ath_power_restore_power_state(sc);

        DPRINTF(sc, ATH_DEBUG_MODE, "%s: RX filter 0x%x\n", __func__, rfilt);
}

static void
ath_update_mcast(struct ifnet *ifp)
{
        struct ath_softc *sc = ifp->if_softc;
        u_int32_t mfilt[2];

        /* calculate and install multicast filter */
        if ((ifp->if_flags & IFF_ALLMULTI) == 0) {
                struct ifmultiaddr *ifma;
                /*
                 * Merge multicast addresses to form the hardware filter.
                 */
                mfilt[0] = mfilt[1] = 0;
#if 0
                if_maddr_rlock(ifp);    /* XXX need some fiddling to remove? */
#endif
                TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                        caddr_t dl;
                        u_int32_t val;
                        u_int8_t pos;

                        /* calculate XOR of eight 6bit values */
                        dl = LLADDR((struct sockaddr_dl *) ifma->ifma_addr);
                        val = LE_READ_4(dl + 0);
                        pos = (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
                        val = LE_READ_4(dl + 3);
                        pos ^= (val >> 18) ^ (val >> 12) ^ (val >> 6) ^ val;
                        pos &= 0x3f;
                        mfilt[pos / 32] |= (1 << (pos % 32));
                }
#if 0
                if_maddr_runlock(ifp);
#endif
        } else
                mfilt[0] = mfilt[1] = ~0;
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        ath_hal_setmcastfilter(sc->sc_ah, mfilt[0], mfilt[1]);
        ath_power_restore_power_state(sc);
        DPRINTF(sc, ATH_DEBUG_MODE, "%s: MC filter %08x:%08x\n",
                __func__, mfilt[0], mfilt[1]);
}

void
ath_mode_init(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ath_hal *ah = sc->sc_ah;
        u_int32_t rfilt;

        /* configure rx filter */
        rfilt = ath_calcrxfilter(sc);
        ath_hal_setrxfilter(ah, rfilt);

        /* configure operational mode */
        ath_hal_setopmode(ah);

#if 0
        DPRINTF(sc, ATH_DEBUG_STATE | ATH_DEBUG_MODE,
            "%s: ah=%p, ifp=%p, if_addr=%p\n",
            __func__,
            ah,
            ifp,
            (ifp == NULL) ? NULL : ifp->if_addr);
#endif

        /* handle any link-level address change */
        ath_hal_setmac(ah, IF_LLADDR(ifp));

        /* calculate and install multicast filter */
        ath_update_mcast(ifp);
}

/*
 * Set the slot time based on the current setting.
 */
void
ath_setslottime(struct ath_softc *sc)
{
        struct ieee80211com *ic = sc->sc_ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        u_int usec;

        if (IEEE80211_IS_CHAN_HALF(ic->ic_curchan))
                usec = 13;
        else if (IEEE80211_IS_CHAN_QUARTER(ic->ic_curchan))
                usec = 21;
        else if (IEEE80211_IS_CHAN_ANYG(ic->ic_curchan)) {
                /* honor short/long slot time only in 11g */
                /* XXX shouldn't honor on pure g or turbo g channel */
                if (ic->ic_flags & IEEE80211_F_SHSLOT)
                        usec = HAL_SLOT_TIME_9;
                else
                        usec = HAL_SLOT_TIME_20;
        } else
                usec = HAL_SLOT_TIME_9;

        DPRINTF(sc, ATH_DEBUG_RESET,
            "%s: chan %u MHz flags 0x%x %s slot, %u usec\n",
            __func__, ic->ic_curchan->ic_freq, ic->ic_curchan->ic_flags,
            ic->ic_flags & IEEE80211_F_SHSLOT ? "short" : "long", usec);

        /* Wake up the hardware first before updating the slot time */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        ath_hal_setslottime(ah, usec);
        ath_power_restore_power_state(sc);
        sc->sc_updateslot = OK;
}

/*
 * Callback from the 802.11 layer to update the
 * slot time based on the current setting.
 */
static void
ath_updateslot(struct ifnet *ifp)
{
        struct ath_softc *sc = ifp->if_softc;
        struct ieee80211com *ic = ifp->if_l2com;

        /*
         * When not coordinating the BSS, change the hardware
         * immediately.  For other operation we defer the change
         * until beacon updates have propagated to the stations.
         *
         * XXX sc_updateslot isn't changed behind a lock?
         */
        if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
            ic->ic_opmode == IEEE80211_M_MBSS)
                sc->sc_updateslot = UPDATE;
        else
                ath_setslottime(sc);
}

/*
 * Append the contents of src to dst; both queues
 * are assumed to be locked.
 */
void
ath_txqmove(struct ath_txq *dst, struct ath_txq *src)
{

        ATH_TXQ_LOCK_ASSERT(src);
        ATH_TXQ_LOCK_ASSERT(dst);

        TAILQ_CONCAT(&dst->axq_q, &src->axq_q, bf_list);
        dst->axq_link = src->axq_link;
        src->axq_link = NULL;
        dst->axq_depth += src->axq_depth;
        dst->axq_aggr_depth += src->axq_aggr_depth;
        src->axq_depth = 0;
        src->axq_aggr_depth = 0;
}

/*
 * Reset the hardware, with no loss.
 *
 * This can't be used for a general case reset.
 */
static void
ath_reset_proc(void *arg, int pending)
{
        struct ath_softc *sc = arg;
        struct ifnet *ifp = sc->sc_ifp;

#if 0
        if_printf(ifp, "%s: resetting\n", __func__);
#endif
        wlan_serialize_enter();
        ath_reset(ifp, ATH_RESET_NOLOSS);
        wlan_serialize_exit();
}

/*
 * Reset the hardware after detecting beacons have stopped.
 */
static void
ath_bstuck_proc(void *arg, int pending)
{
        struct ath_softc *sc = arg;
        struct ifnet *ifp = sc->sc_ifp;
        uint32_t hangs = 0;

        wlan_serialize_enter();
        if (ath_hal_gethangstate(sc->sc_ah, 0xff, &hangs) && hangs != 0)
                if_printf(ifp, "bb hang detected (0x%x)\n", hangs);

#ifdef  ATH_DEBUG_ALQ
        if (if_ath_alq_checkdebug(&sc->sc_alq, ATH_ALQ_STUCK_BEACON))
                if_ath_alq_post(&sc->sc_alq, ATH_ALQ_STUCK_BEACON, 0, NULL);
#endif

        if_printf(ifp, "stuck beacon; resetting (bmiss count %u)\n",
                sc->sc_bmisscount);
        sc->sc_stats.ast_bstuck++;
        /*
         * This assumes that there's no simultaneous channel mode change
         * occuring.
         */
        ath_reset(ifp, ATH_RESET_NOLOSS);
        wlan_serialize_exit();
}

static void
ath_load_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        bus_addr_t *paddr = (bus_addr_t*) arg;
        KASSERT(error == 0, ("error %u on bus_dma callback", error));
        *paddr = segs->ds_addr;
}

/*
 * Allocate the descriptors and appropriate DMA tag/setup.
 *
 * For some situations (eg EDMA TX completion), there isn't a requirement
 * for the ath_buf entries to be allocated.
 */
int
ath_descdma_alloc_desc(struct ath_softc *sc,
        struct ath_descdma *dd, ath_bufhead *head,
        const char *name, int ds_size, int ndesc)
{
#define DS2PHYS(_dd, _ds) \
        ((_dd)->dd_desc_paddr + ((caddr_t)(_ds) - (caddr_t)(_dd)->dd_desc))
#define ATH_DESC_4KB_BOUND_CHECK(_daddr, _len) \
        ((((u_int32_t)(_daddr) & 0xFFF) > (0x1000 - (_len))) ? 1 : 0)
        struct ifnet *ifp = sc->sc_ifp;
        int error;

        dd->dd_descsize = ds_size;

        DPRINTF(sc, ATH_DEBUG_RESET,
            "%s: %s DMA: %u desc, %d bytes per descriptor\n",
            __func__, name, ndesc, dd->dd_descsize);

        dd->dd_name = name;
        dd->dd_desc_len = dd->dd_descsize * ndesc;

        /*
         * Merlin work-around:
         * Descriptors that cross the 4KB boundary can't be used.
         * Assume one skipped descriptor per 4KB page.
         */
        if (! ath_hal_split4ktrans(sc->sc_ah)) {
                int numpages = dd->dd_desc_len / 4096;
                dd->dd_desc_len += ds_size * numpages;
        }

        /*
         * Setup DMA descriptor area.
         *
         * BUS_DMA_ALLOCNOW is not used; we never use bounce
         * buffers for the descriptors themselves.
         */
        error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), /* parent */
                       PAGE_SIZE, 0,            /* alignment, bounds */
                       BUS_SPACE_MAXADDR_32BIT, /* lowaddr */
                       BUS_SPACE_MAXADDR,       /* highaddr */
                       NULL, NULL,              /* filter, filterarg */
                       dd->dd_desc_len,         /* maxsize */
                       1,                       /* nsegments */
                       dd->dd_desc_len,         /* maxsegsize */
                       0,                       /* flags */
                       &dd->dd_dmat);
        if (error != 0) {
                if_printf(ifp, "cannot allocate %s DMA tag\n", dd->dd_name);
                return error;
        }

        /* allocate descriptors */
        error = bus_dmamem_alloc(dd->dd_dmat, (void**) &dd->dd_desc,
                                 BUS_DMA_NOWAIT | BUS_DMA_COHERENT,
                                 &dd->dd_dmamap);
        if (error != 0) {
                if_printf(ifp, "unable to alloc memory for %u %s descriptors, "
                        "error %u\n", ndesc, dd->dd_name, error);
                goto fail1;
        }

        error = bus_dmamap_load(dd->dd_dmat, dd->dd_dmamap,
                                dd->dd_desc, dd->dd_desc_len,
                                ath_load_cb, &dd->dd_desc_paddr,
                                BUS_DMA_NOWAIT);
        if (error != 0) {
                if_printf(ifp, "unable to map %s descriptors, error %u\n",
                        dd->dd_name, error);
                goto fail2;
        }

        DPRINTF(sc, ATH_DEBUG_RESET, "%s: %s DMA map: %p (%lu) -> %p (%lu)\n",
            __func__, dd->dd_name, (uint8_t *) dd->dd_desc,
            (u_long) dd->dd_desc_len, (caddr_t) dd->dd_desc_paddr,
            /*XXX*/ (u_long) dd->dd_desc_len);

        return (0);

fail2:
        bus_dmamem_free(dd->dd_dmat, dd->dd_desc, dd->dd_dmamap);
fail1:
        bus_dma_tag_destroy(dd->dd_dmat);
        memset(dd, 0, sizeof(*dd));
        return error;
#undef DS2PHYS
#undef ATH_DESC_4KB_BOUND_CHECK
}

int
ath_descdma_setup(struct ath_softc *sc,
        struct ath_descdma *dd, ath_bufhead *head,
        const char *name, int ds_size, int nbuf, int ndesc)
{
#define DS2PHYS(_dd, _ds) \
        ((_dd)->dd_desc_paddr + ((caddr_t)(_ds) - (caddr_t)(_dd)->dd_desc))
#define ATH_DESC_4KB_BOUND_CHECK(_daddr, _len) \
        ((((u_int32_t)(_daddr) & 0xFFF) > (0x1000 - (_len))) ? 1 : 0)
        struct ifnet *ifp = sc->sc_ifp;
        uint8_t *ds;
        struct ath_buf *bf;
        int i, bsize, error;

        /* Allocate descriptors */
        error = ath_descdma_alloc_desc(sc, dd, head, name, ds_size,
            nbuf * ndesc);

        /* Assume any errors during allocation were dealt with */
        if (error != 0) {
                return (error);
        }

        ds = (uint8_t *) dd->dd_desc;

        /* allocate rx buffers */
        bsize = sizeof(struct ath_buf) * nbuf;
        bf = kmalloc(bsize, M_ATHDEV, M_INTWAIT|M_ZERO);
        if (bf == NULL) {
                if_printf(ifp, "malloc of %s buffers failed, size %u\n",
                        dd->dd_name, bsize);
                goto fail3;
        }
        dd->dd_bufptr = bf;

        TAILQ_INIT(head);
        for (i = 0; i < nbuf; i++, bf++, ds += (ndesc * dd->dd_descsize)) {
                bf->bf_desc = (struct ath_desc *) ds;
                bf->bf_daddr = DS2PHYS(dd, ds);
                if (! ath_hal_split4ktrans(sc->sc_ah)) {
                        /*
                         * Merlin WAR: Skip descriptor addresses which
                         * cause 4KB boundary crossing along any point
                         * in the descriptor.
                         */
                         if (ATH_DESC_4KB_BOUND_CHECK(bf->bf_daddr,
                             dd->dd_descsize)) {
                                /* Start at the next page */
                                ds += 0x1000 - (bf->bf_daddr & 0xFFF);
                                bf->bf_desc = (struct ath_desc *) ds;
                                bf->bf_daddr = DS2PHYS(dd, ds);
                        }
                }
                error = bus_dmamap_create(sc->sc_dmat, BUS_DMA_NOWAIT,
                                &bf->bf_dmamap);
                if (error != 0) {
                        if_printf(ifp, "unable to create dmamap for %s "
                                "buffer %u, error %u\n", dd->dd_name, i, error);
                        ath_descdma_cleanup(sc, dd, head);
                        return error;
                }
                bf->bf_lastds = bf->bf_desc;    /* Just an initial value */
                TAILQ_INSERT_TAIL(head, bf, bf_list);
        }

        /*
         * XXX TODO: ensure that ds doesn't overflow the descriptor
         * allocation otherwise weird stuff will occur and crash your
         * machine.
         */
        return 0;
        /* XXX this should likely just call ath_descdma_cleanup() */
fail3:
        bus_dmamap_unload(dd->dd_dmat, dd->dd_dmamap);
        bus_dmamem_free(dd->dd_dmat, dd->dd_desc, dd->dd_dmamap);
        bus_dma_tag_destroy(dd->dd_dmat);
        memset(dd, 0, sizeof(*dd));
        return error;
#undef DS2PHYS
#undef ATH_DESC_4KB_BOUND_CHECK
}

/*
 * Allocate ath_buf entries but no descriptor contents.
 *
 * This is for RX EDMA where the descriptors are the header part of
 * the RX buffer.
 */
int
ath_descdma_setup_rx_edma(struct ath_softc *sc,
        struct ath_descdma *dd, ath_bufhead *head,
        const char *name, int nbuf, int rx_status_len)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ath_buf *bf;
        int i, bsize, error;

        DPRINTF(sc, ATH_DEBUG_RESET, "%s: %s DMA: %u buffers\n",
            __func__, name, nbuf);

        dd->dd_name = name;
        /*
         * This is (mostly) purely for show.  We're not allocating any actual
         * descriptors here as EDMA RX has the descriptor be part
         * of the RX buffer.
         *
         * However, dd_desc_len is used by ath_descdma_free() to determine
         * whether we have already freed this DMA mapping.
         */
        dd->dd_desc_len = rx_status_len * nbuf;
        dd->dd_descsize = rx_status_len;

        /* allocate rx buffers */
        bsize = sizeof(struct ath_buf) * nbuf;
        bf = kmalloc(bsize, M_ATHDEV, M_INTWAIT | M_ZERO);
        if (bf == NULL) {
                if_printf(ifp, "malloc of %s buffers failed, size %u\n",
                        dd->dd_name, bsize);
                error = ENOMEM;
                goto fail3;
        }
        dd->dd_bufptr = bf;

        TAILQ_INIT(head);
        for (i = 0; i < nbuf; i++, bf++) {
                bf->bf_desc = NULL;
                bf->bf_daddr = 0;
                bf->bf_lastds = NULL;   /* Just an initial value */

                error = bus_dmamap_create(sc->sc_dmat, BUS_DMA_NOWAIT,
                                &bf->bf_dmamap);
                if (error != 0) {
                        if_printf(ifp, "unable to create dmamap for %s "
                                "buffer %u, error %u\n", dd->dd_name, i, error);
                        ath_descdma_cleanup(sc, dd, head);
                        return error;
                }
                TAILQ_INSERT_TAIL(head, bf, bf_list);
        }
        return 0;
fail3:
        memset(dd, 0, sizeof(*dd));
        return error;
}

void
ath_descdma_cleanup(struct ath_softc *sc,
        struct ath_descdma *dd, ath_bufhead *head)
{
        struct ath_buf *bf;
        struct ieee80211_node *ni;
        int do_warning = 0;

        if (dd->dd_dmamap != 0) {
                bus_dmamap_unload(dd->dd_dmat, dd->dd_dmamap);
                bus_dmamem_free(dd->dd_dmat, dd->dd_desc, dd->dd_dmamap);
                bus_dma_tag_destroy(dd->dd_dmat);
        }

        if (head != NULL) {
                TAILQ_FOREACH(bf, head, bf_list) {
                        if (bf->bf_m) {
                                /*
                                 * XXX warn if there's buffers here.
                                 * XXX it should have been freed by the
                                 * owner!
                                 */
                                
                                if (do_warning == 0) {
                                        do_warning = 1;
                                        device_printf(sc->sc_dev,
                                            "%s: %s: mbuf should've been"
                                            " unmapped/freed!\n",
                                            __func__,
                                            dd->dd_name);
                                }
                                bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
                                    BUS_DMASYNC_POSTREAD);
                                bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
                                m_freem(bf->bf_m);
                                bf->bf_m = NULL;
                        }
                        if (bf->bf_dmamap != NULL) {
                                bus_dmamap_destroy(sc->sc_dmat, bf->bf_dmamap);
                                bf->bf_dmamap = NULL;
                        }
                        ni = bf->bf_node;
                        bf->bf_node = NULL;
                        if (ni != NULL) {
                                /*
                                 * Reclaim node reference.
                                 */
                                ieee80211_free_node(ni);
                        }
                }
        }

        if (head != NULL)
                TAILQ_INIT(head);

        if (dd->dd_bufptr != NULL)
                kfree(dd->dd_bufptr, M_ATHDEV);
        memset(dd, 0, sizeof(*dd));
}

static int
ath_desc_alloc(struct ath_softc *sc)
{
        int error;

        error = ath_descdma_setup(sc, &sc->sc_txdma, &sc->sc_txbuf,
                    "tx", sc->sc_tx_desclen, ath_txbuf, ATH_MAX_SCATTER);
        if (error != 0) {
                return error;
        }
        sc->sc_txbuf_cnt = ath_txbuf;

        error = ath_descdma_setup(sc, &sc->sc_txdma_mgmt, &sc->sc_txbuf_mgmt,
                    "tx_mgmt", sc->sc_tx_desclen, ath_txbuf_mgmt,
                    ATH_TXDESC);
        if (error != 0) {
                ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
                return error;
        }

        /*
         * XXX mark txbuf_mgmt frames with ATH_BUF_MGMT, so the
         * flag doesn't have to be set in ath_getbuf_locked().
         */

        error = ath_descdma_setup(sc, &sc->sc_bdma, &sc->sc_bbuf,
                        "beacon", sc->sc_tx_desclen, ATH_BCBUF, 1);
        if (error != 0) {
                ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
                ath_descdma_cleanup(sc, &sc->sc_txdma_mgmt,
                    &sc->sc_txbuf_mgmt);
                return error;
        }
        return 0;
}

static void
ath_desc_free(struct ath_softc *sc)
{

        if (sc->sc_bdma.dd_desc_len != 0)
                ath_descdma_cleanup(sc, &sc->sc_bdma, &sc->sc_bbuf);
        if (sc->sc_txdma.dd_desc_len != 0)
                ath_descdma_cleanup(sc, &sc->sc_txdma, &sc->sc_txbuf);
        if (sc->sc_txdma_mgmt.dd_desc_len != 0)
                ath_descdma_cleanup(sc, &sc->sc_txdma_mgmt,
                    &sc->sc_txbuf_mgmt);
}

static struct ieee80211_node *
ath_node_alloc(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        const size_t space = sizeof(struct ath_node) + sc->sc_rc->arc_space;
        struct ath_node *an;

        an = kmalloc(space, M_80211_NODE, M_INTWAIT|M_ZERO);
        if (an == NULL) {
                /* XXX stat+msg */
                return NULL;
        }
        ath_rate_node_init(sc, an);

        /* Setup the mutex - there's no associd yet so set the name to NULL */
        ksnprintf(an->an_name, sizeof(an->an_name), "%s: node %p",
            device_get_nameunit(sc->sc_dev), an);
#if 0
        mtx_init(&an->an_mtx, an->an_name, NULL, MTX_DEF);
#endif

        /* XXX setup ath_tid */
        ath_tx_tid_init(sc, an);

        DPRINTF(sc, ATH_DEBUG_NODE, "%s: %s: an %p\n", __func__,
            ath_hal_ether_sprintf(mac), an);
        return &an->an_node;
}

static void
ath_node_cleanup(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;

        DPRINTF(sc, ATH_DEBUG_NODE, "%s: %s: an %p\n", __func__,
            ath_hal_ether_sprintf(ni->ni_macaddr), ATH_NODE(ni));

        /* Cleanup ath_tid, free unused bufs, unlink bufs in TXQ */
        ath_tx_node_flush(sc, ATH_NODE(ni));
        ath_rate_node_cleanup(sc, ATH_NODE(ni));
        sc->sc_node_cleanup(ni);
}

static void
ath_node_free(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;

        DPRINTF(sc, ATH_DEBUG_NODE, "%s: %s: an %p\n", __func__,
            ath_hal_ether_sprintf(ni->ni_macaddr), ATH_NODE(ni));
#if 0
        mtx_destroy(&ATH_NODE(ni)->an_mtx);
#endif
        sc->sc_node_free(ni);
}

static void
ath_node_getsignal(const struct ieee80211_node *ni, int8_t *rssi, int8_t *noise)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;

        *rssi = ic->ic_node_getrssi(ni);
        if (ni->ni_chan != IEEE80211_CHAN_ANYC)
                *noise = ath_hal_getchannoise(ah, ni->ni_chan);
        else
                *noise = -95;           /* nominally correct */
}

/*
 * Set the default antenna.
 */
void
ath_setdefantenna(struct ath_softc *sc, u_int antenna)
{
        struct ath_hal *ah = sc->sc_ah;

        /* XXX block beacon interrupts */
        ath_hal_setdefantenna(ah, antenna);
        if (sc->sc_defant != antenna)
                sc->sc_stats.ast_ant_defswitch++;
        sc->sc_defant = antenna;
        sc->sc_rxotherant = 0;
}

static void
ath_txq_init(struct ath_softc *sc, struct ath_txq *txq, int qnum)
{
        txq->axq_qnum = qnum;
        txq->axq_ac = 0;
        txq->axq_depth = 0;
        txq->axq_aggr_depth = 0;
        txq->axq_intrcnt = 0;
        txq->axq_link = NULL;
        txq->axq_softc = sc;
        TAILQ_INIT(&txq->axq_q);
        TAILQ_INIT(&txq->axq_tidq);
        TAILQ_INIT(&txq->fifo.axq_q);
        ATH_TXQ_LOCK_INIT(sc, txq);
}

/*
 * Setup a h/w transmit queue.
 */
static struct ath_txq *
ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
{
#define N(a)    (sizeof(a)/sizeof(a[0]))
        struct ath_hal *ah = sc->sc_ah;
        HAL_TXQ_INFO qi;
        int qnum;

        memset(&qi, 0, sizeof(qi));
        qi.tqi_subtype = subtype;
        qi.tqi_aifs = HAL_TXQ_USEDEFAULT;
        qi.tqi_cwmin = HAL_TXQ_USEDEFAULT;
        qi.tqi_cwmax = HAL_TXQ_USEDEFAULT;
        /*
         * Enable interrupts only for EOL and DESC conditions.
         * We mark tx descriptors to receive a DESC interrupt
         * when a tx queue gets deep; otherwise waiting for the
         * EOL to reap descriptors.  Note that this is done to
         * reduce interrupt load and this only defers reaping
         * descriptors, never transmitting frames.  Aside from
         * reducing interrupts this also permits more concurrency.
         * The only potential downside is if the tx queue backs
         * up in which case the top half of the kernel may backup
         * due to a lack of tx descriptors.
         */
        if (sc->sc_isedma)
                qi.tqi_qflags = HAL_TXQ_TXEOLINT_ENABLE |
                    HAL_TXQ_TXOKINT_ENABLE;
        else
                qi.tqi_qflags = HAL_TXQ_TXEOLINT_ENABLE |
                    HAL_TXQ_TXDESCINT_ENABLE;

        qnum = ath_hal_setuptxqueue(ah, qtype, &qi);
        if (qnum == -1) {
                /*
                 * NB: don't print a message, this happens
                 * normally on parts with too few tx queues
                 */
                return NULL;
        }
        if (qnum >= N(sc->sc_txq)) {
                device_printf(sc->sc_dev,
                        "hal qnum %u out of range, max %zu!\n",
                        qnum, N(sc->sc_txq));
                ath_hal_releasetxqueue(ah, qnum);
                return NULL;
        }
        if (!ATH_TXQ_SETUP(sc, qnum)) {
                ath_txq_init(sc, &sc->sc_txq[qnum], qnum);
                sc->sc_txqsetup |= 1<<qnum;
        }
        return &sc->sc_txq[qnum];
#undef N
}

/*
 * Setup a hardware data transmit queue for the specified
 * access control.  The hal may not support all requested
 * queues in which case it will return a reference to a
 * previously setup queue.  We record the mapping from ac's
 * to h/w queues for use by ath_tx_start and also track
 * the set of h/w queues being used to optimize work in the
 * transmit interrupt handler and related routines.
 */
static int
ath_tx_setup(struct ath_softc *sc, int ac, int haltype)
{
#define N(a)    (sizeof(a)/sizeof(a[0]))
        struct ath_txq *txq;

        if (ac >= N(sc->sc_ac2q)) {
                device_printf(sc->sc_dev, "AC %u out of range, max %zu!\n",
                        ac, N(sc->sc_ac2q));
                return 0;
        }
        txq = ath_txq_setup(sc, HAL_TX_QUEUE_DATA, haltype);
        if (txq != NULL) {
                txq->axq_ac = ac;
                sc->sc_ac2q[ac] = txq;
                return 1;
        } else
                return 0;
#undef N
}

/*
 * Update WME parameters for a transmit queue.
 */
static int
ath_txq_update(struct ath_softc *sc, int ac)
{
#define ATH_EXPONENT_TO_VALUE(v)        ((1<<v)-1)
#define ATH_TXOP_TO_US(v)               (v<<5)
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_txq *txq = sc->sc_ac2q[ac];
        struct wmeParams *wmep = &ic->ic_wme.wme_chanParams.cap_wmeParams[ac];
        struct ath_hal *ah = sc->sc_ah;
        HAL_TXQ_INFO qi;

        ath_hal_gettxqueueprops(ah, txq->axq_qnum, &qi);
#ifdef IEEE80211_SUPPORT_TDMA
        if (sc->sc_tdma) {
                /*
                 * AIFS is zero so there's no pre-transmit wait.  The
                 * burst time defines the slot duration and is configured
                 * through net80211.  The QCU is setup to not do post-xmit
                 * back off, lockout all lower-priority QCU's, and fire
                 * off the DMA beacon alert timer which is setup based
                 * on the slot configuration.
                 */
                qi.tqi_qflags = HAL_TXQ_TXOKINT_ENABLE
                              | HAL_TXQ_TXERRINT_ENABLE
                              | HAL_TXQ_TXURNINT_ENABLE
                              | HAL_TXQ_TXEOLINT_ENABLE
                              | HAL_TXQ_DBA_GATED
                              | HAL_TXQ_BACKOFF_DISABLE
                              | HAL_TXQ_ARB_LOCKOUT_GLOBAL
                              ;
                qi.tqi_aifs = 0;
                /* XXX +dbaprep? */
                qi.tqi_readyTime = sc->sc_tdmaslotlen;
                qi.tqi_burstTime = qi.tqi_readyTime;
        } else {
#endif
                /*
                 * XXX shouldn't this just use the default flags
                 * used in the previous queue setup?
                 */
                qi.tqi_qflags = HAL_TXQ_TXOKINT_ENABLE
                              | HAL_TXQ_TXERRINT_ENABLE
                              | HAL_TXQ_TXDESCINT_ENABLE
                              | HAL_TXQ_TXURNINT_ENABLE
                              | HAL_TXQ_TXEOLINT_ENABLE
                              ;
                qi.tqi_aifs = wmep->wmep_aifsn;
                qi.tqi_cwmin = ATH_EXPONENT_TO_VALUE(wmep->wmep_logcwmin);
                qi.tqi_cwmax = ATH_EXPONENT_TO_VALUE(wmep->wmep_logcwmax);
                qi.tqi_readyTime = 0;
                qi.tqi_burstTime = ATH_TXOP_TO_US(wmep->wmep_txopLimit);
#ifdef IEEE80211_SUPPORT_TDMA
        }
#endif

        DPRINTF(sc, ATH_DEBUG_RESET,
            "%s: Q%u qflags 0x%x aifs %u cwmin %u cwmax %u burstTime %u\n",
            __func__, txq->axq_qnum, qi.tqi_qflags,
            qi.tqi_aifs, qi.tqi_cwmin, qi.tqi_cwmax, qi.tqi_burstTime);

        if (!ath_hal_settxqueueprops(ah, txq->axq_qnum, &qi)) {
                if_printf(ifp, "unable to update hardware queue "
                        "parameters for %s traffic!\n",
                        ieee80211_wme_acnames[ac]);
                return 0;
        } else {
                ath_hal_resettxqueue(ah, txq->axq_qnum); /* push to h/w */
                return 1;
        }
#undef ATH_TXOP_TO_US
#undef ATH_EXPONENT_TO_VALUE
}

/*
 * Callback from the 802.11 layer to update WME parameters.
 */
int
ath_wme_update(struct ieee80211com *ic)
{
        struct ath_softc *sc = ic->ic_ifp->if_softc;

        return !ath_txq_update(sc, WME_AC_BE) ||
            !ath_txq_update(sc, WME_AC_BK) ||
            !ath_txq_update(sc, WME_AC_VI) ||
            !ath_txq_update(sc, WME_AC_VO) ? EIO : 0;
}

/*
 * Reclaim resources for a setup queue.
 */
static void
ath_tx_cleanupq(struct ath_softc *sc, struct ath_txq *txq)
{

        ath_hal_releasetxqueue(sc->sc_ah, txq->axq_qnum);
        sc->sc_txqsetup &= ~(1<<txq->axq_qnum);
        ATH_TXQ_LOCK_DESTROY(txq);
}

/*
 * Reclaim all tx queue resources.
 */
static void
ath_tx_cleanup(struct ath_softc *sc)
{
        int i;

        ATH_TXBUF_LOCK_DESTROY(sc);
        for (i = 0; i < HAL_NUM_TX_QUEUES; i++)
                if (ATH_TXQ_SETUP(sc, i))
                        ath_tx_cleanupq(sc, &sc->sc_txq[i]);
}

/*
 * Return h/w rate index for an IEEE rate (w/o basic rate bit)
 * using the current rates in sc_rixmap.
 */
int
ath_tx_findrix(const struct ath_softc *sc, uint8_t rate)
{
        int rix = sc->sc_rixmap[rate];
        /* NB: return lowest rix for invalid rate */
        return (rix == 0xff ? 0 : rix);
}

static void
ath_tx_update_stats(struct ath_softc *sc, struct ath_tx_status *ts,
    struct ath_buf *bf)
{
        struct ieee80211_node *ni = bf->bf_node;
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        int sr, lr, pri;

        if (ts->ts_status == 0) {
                u_int8_t txant = ts->ts_antenna;
                sc->sc_stats.ast_ant_tx[txant]++;
                sc->sc_ant_tx[txant]++;
                if (ts->ts_finaltsi != 0)
                        sc->sc_stats.ast_tx_altrate++;
                pri = M_WME_GETAC(bf->bf_m);
                if (pri >= WME_AC_VO)
                        ic->ic_wme.wme_hipri_traffic++;
                if ((bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) == 0)
                        ni->ni_inact = ni->ni_inact_reload;
        } else {
                if (ts->ts_status & HAL_TXERR_XRETRY)
                        sc->sc_stats.ast_tx_xretries++;
                if (ts->ts_status & HAL_TXERR_FIFO)
                        sc->sc_stats.ast_tx_fifoerr++;
                if (ts->ts_status & HAL_TXERR_FILT)
                        sc->sc_stats.ast_tx_filtered++;
                if (ts->ts_status & HAL_TXERR_XTXOP)
                        sc->sc_stats.ast_tx_xtxop++;
                if (ts->ts_status & HAL_TXERR_TIMER_EXPIRED)
                        sc->sc_stats.ast_tx_timerexpired++;

                if (bf->bf_m->m_flags & M_FF)
                        sc->sc_stats.ast_ff_txerr++;
        }
        /* XXX when is this valid? */
        if (ts->ts_flags & HAL_TX_DESC_CFG_ERR)
                sc->sc_stats.ast_tx_desccfgerr++;
        /*
         * This can be valid for successful frame transmission!
         * If there's a TX FIFO underrun during aggregate transmission,
         * the MAC will pad the rest of the aggregate with delimiters.
         * If a BA is returned, the frame is marked as "OK" and it's up
         * to the TX completion code to notice which frames weren't
         * successfully transmitted.
         */
        if (ts->ts_flags & HAL_TX_DATA_UNDERRUN)
                sc->sc_stats.ast_tx_data_underrun++;
        if (ts->ts_flags & HAL_TX_DELIM_UNDERRUN)
                sc->sc_stats.ast_tx_delim_underrun++;

        sr = ts->ts_shortretry;
        lr = ts->ts_longretry;
        sc->sc_stats.ast_tx_shortretry += sr;
        sc->sc_stats.ast_tx_longretry += lr;

}

/*
 * The default completion. If fail is 1, this means
 * "please don't retry the frame, and just return -1 status
 * to the net80211 stack.
 */
void
ath_tx_default_comp(struct ath_softc *sc, struct ath_buf *bf, int fail)
{
        struct ath_tx_status *ts = &bf->bf_status.ds_txstat;
        int st;

        if (fail == 1)
                st = -1;
        else
                st = ((bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) == 0) ?
                    ts->ts_status : HAL_TXERR_XRETRY;

#if 0
        if (bf->bf_state.bfs_dobaw)
                device_printf(sc->sc_dev,
                    "%s: bf %p: seqno %d: dobaw should've been cleared!\n",
                    __func__,
                    bf,
                    SEQNO(bf->bf_state.bfs_seqno));
#endif
        if (bf->bf_next != NULL)
                device_printf(sc->sc_dev,
                    "%s: bf %p: seqno %d: bf_next not NULL!\n",
                    __func__,
                    bf,
                    SEQNO(bf->bf_state.bfs_seqno));

        /*
         * Check if the node software queue is empty; if so
         * then clear the TIM.
         *
         * This needs to be done before the buffer is freed as
         * otherwise the node reference will have been released
         * and the node may not actually exist any longer.
         *
         * XXX I don't like this belonging here, but it's cleaner
         * to do it here right now then all the other places
         * where ath_tx_default_comp() is called.
         *
         * XXX TODO: during drain, ensure that the callback is
         * being called so we get a chance to update the TIM.
         */
        if (bf->bf_node) {
                ATH_TX_LOCK(sc);
                ath_tx_update_tim(sc, bf->bf_node, 0);
                ATH_TX_UNLOCK(sc);
        }

        /*
         * Do any tx complete callback.  Note this must
         * be done before releasing the node reference.
         * This will free the mbuf, release the net80211
         * node and recycle the ath_buf.
         */
        ath_tx_freebuf(sc, bf, st);
}

/*
 * Update rate control with the given completion status.
 */
void
ath_tx_update_ratectrl(struct ath_softc *sc, struct ieee80211_node *ni,
    struct ath_rc_series *rc, struct ath_tx_status *ts, int frmlen,
    int nframes, int nbad)
{
        struct ath_node *an;

        /* Only for unicast frames */
        if (ni == NULL)
                return;

        an = ATH_NODE(ni);
        ATH_NODE_UNLOCK_ASSERT(an);

        if ((ts->ts_status & HAL_TXERR_FILT) == 0) {
                ATH_NODE_LOCK(an);
                ath_rate_tx_complete(sc, an, rc, ts, frmlen, nframes, nbad);
                ATH_NODE_UNLOCK(an);
        }
}

/*
 * Process the completion of the given buffer.
 *
 * This calls the rate control update and then the buffer completion.
 * This will either free the buffer or requeue it.  In any case, the
 * bf pointer should be treated as invalid after this function is called.
 */
void
ath_tx_process_buf_completion(struct ath_softc *sc, struct ath_txq *txq,
    struct ath_tx_status *ts, struct ath_buf *bf)
{
        struct ieee80211_node *ni = bf->bf_node;
        struct ath_node *an = NULL;

        ATH_TX_UNLOCK_ASSERT(sc);
        ATH_TXQ_UNLOCK_ASSERT(txq);

        /* If unicast frame, update general statistics */
        if (ni != NULL) {
                an = ATH_NODE(ni);
                /* update statistics */
                ath_tx_update_stats(sc, ts, bf);
        }

        /*
         * Call the completion handler.
         * The completion handler is responsible for
         * calling the rate control code.
         *
         * Frames with no completion handler get the
         * rate control code called here.
         */
        if (bf->bf_comp == NULL) {
                if ((ts->ts_status & HAL_TXERR_FILT) == 0 &&
                    (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) == 0) {
                        /*
                         * XXX assume this isn't an aggregate
                         * frame.
                         */
                        ath_tx_update_ratectrl(sc, ni,
                             bf->bf_state.bfs_rc, ts,
                            bf->bf_state.bfs_pktlen, 1,
                            (ts->ts_status == 0 ? 0 : 1));
                }
                ath_tx_default_comp(sc, bf, 0);
        } else
                bf->bf_comp(sc, bf, 0);
}



/*
 * Process completed xmit descriptors from the specified queue.
 * Kick the packet scheduler if needed. This can occur from this
 * particular task.
 */
static int
ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq, int dosched)
{
        struct ath_hal *ah = sc->sc_ah;
        struct ath_buf *bf;
        struct ath_desc *ds;
        struct ath_tx_status *ts;
        struct ieee80211_node *ni;
#ifdef  IEEE80211_SUPPORT_SUPERG
        struct ieee80211com *ic = sc->sc_ifp->if_l2com;
#endif  /* IEEE80211_SUPPORT_SUPERG */
        int nacked;
        HAL_STATUS status;

        DPRINTF(sc, ATH_DEBUG_TX_PROC, "%s: tx queue %u head %p link %p\n",
                __func__, txq->axq_qnum,
                (caddr_t)(uintptr_t) ath_hal_gettxbuf(sc->sc_ah, txq->axq_qnum),
                txq->axq_link);

        ATH_KTR(sc, ATH_KTR_TXCOMP, 4,
            "ath_tx_processq: txq=%u head %p link %p depth %p",
            txq->axq_qnum,
            (caddr_t)(uintptr_t) ath_hal_gettxbuf(sc->sc_ah, txq->axq_qnum),
            txq->axq_link,
            txq->axq_depth);

        nacked = 0;
        for (;;) {
                ATH_TXQ_LOCK(txq);
                txq->axq_intrcnt = 0;   /* reset periodic desc intr count */
                bf = TAILQ_FIRST(&txq->axq_q);
                if (bf == NULL) {
                        ATH_TXQ_UNLOCK(txq);
                        break;
                }
                ds = bf->bf_lastds;     /* XXX must be setup correctly! */
                ts = &bf->bf_status.ds_txstat;

                status = ath_hal_txprocdesc(ah, ds, ts);
#ifdef ATH_DEBUG
                if (sc->sc_debug & ATH_DEBUG_XMIT_DESC)
                        ath_printtxbuf(sc, bf, txq->axq_qnum, 0,
                            status == HAL_OK);
                else if ((sc->sc_debug & ATH_DEBUG_RESET) && (dosched == 0))
                        ath_printtxbuf(sc, bf, txq->axq_qnum, 0,
                            status == HAL_OK);
#endif
#ifdef  ATH_DEBUG_ALQ
                if (if_ath_alq_checkdebug(&sc->sc_alq,
                    ATH_ALQ_EDMA_TXSTATUS)) {
                        if_ath_alq_post(&sc->sc_alq, ATH_ALQ_EDMA_TXSTATUS,
                        sc->sc_tx_statuslen,
                        (char *) ds);
                }
#endif

                if (status == HAL_EINPROGRESS) {
                        ATH_KTR(sc, ATH_KTR_TXCOMP, 3,
                            "ath_tx_processq: txq=%u, bf=%p ds=%p, HAL_EINPROGRESS",
                            txq->axq_qnum, bf, ds);
                        ATH_TXQ_UNLOCK(txq);
                        break;
                }
                ATH_TXQ_REMOVE(txq, bf, bf_list);

                /*
                 * Sanity check.
                 */
                if (txq->axq_qnum != bf->bf_state.bfs_tx_queue) {
                        device_printf(sc->sc_dev,
                            "%s: TXQ=%d: bf=%p, bfs_tx_queue=%d\n",
                            __func__,
                            txq->axq_qnum,
                            bf,
                            bf->bf_state.bfs_tx_queue);
                }
                if (txq->axq_qnum != bf->bf_last->bf_state.bfs_tx_queue) {
                        device_printf(sc->sc_dev,
                            "%s: TXQ=%d: bf_last=%p, bfs_tx_queue=%d\n",
                            __func__,
                            txq->axq_qnum,
                            bf->bf_last,
                            bf->bf_last->bf_state.bfs_tx_queue);
                }

#if 0
                if (txq->axq_depth > 0) {
                        /*
                         * More frames follow.  Mark the buffer busy
                         * so it's not re-used while the hardware may
                         * still re-read the link field in the descriptor.
                         *
                         * Use the last buffer in an aggregate as that
                         * is where the hardware may be - intermediate
                         * descriptors won't be "busy".
                         */
                        bf->bf_last->bf_flags |= ATH_BUF_BUSY;
                } else
                        txq->axq_link = NULL;
#else
                bf->bf_last->bf_flags |= ATH_BUF_BUSY;
#endif
                if (bf->bf_state.bfs_aggr)
                        txq->axq_aggr_depth--;

                ni = bf->bf_node;

                ATH_KTR(sc, ATH_KTR_TXCOMP, 5,
                    "ath_tx_processq: txq=%u, bf=%p, ds=%p, ni=%p, ts_status=0x%08x",
                    txq->axq_qnum, bf, ds, ni, ts->ts_status);
                /*
                 * If unicast frame was ack'd update RSSI,
                 * including the last rx time used to
                 * workaround phantom bmiss interrupts.
                 */
                if (ni != NULL && ts->ts_status == 0 &&
                    ((bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) == 0)) {
                        nacked++;
                        sc->sc_stats.ast_tx_rssi = ts->ts_rssi;
                        ATH_RSSI_LPF(sc->sc_halstats.ns_avgtxrssi,
                                ts->ts_rssi);
                }
                ATH_TXQ_UNLOCK(txq);

                /*
                 * Update statistics and call completion
                 */
                ath_tx_process_buf_completion(sc, txq, ts, bf);

                /* XXX at this point, bf and ni may be totally invalid */
        }
#ifdef IEEE80211_SUPPORT_SUPERG
        /*
         * Flush fast-frame staging queue when traffic slows.
         */
        if (txq->axq_depth <= 1)
                ieee80211_ff_flush(ic, txq->axq_ac);
#endif

        /* Kick the software TXQ scheduler */
        if (dosched) {
                ATH_TX_LOCK(sc);
                ath_txq_sched(sc, txq);
                ATH_TX_UNLOCK(sc);
        }

        ATH_KTR(sc, ATH_KTR_TXCOMP, 1,
            "ath_tx_processq: txq=%u: done",
            txq->axq_qnum);

        return nacked;
}

#define TXQACTIVE(t, q)         ( (t) & (1 << (q)))

/*
 * Deferred processing of transmit interrupt; special-cased
 * for a single hardware transmit queue (e.g. 5210 and 5211).
 */
static void
ath_tx_proc_q0(void *arg, int npending)
{
        struct ath_softc *sc = arg;
#if 0
        struct ifnet *ifp = sc->sc_ifp;
#endif
        uint32_t txqs;

        wlan_serialize_enter();
        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt++;
        txqs = sc->sc_txq_active;
        sc->sc_txq_active &= ~txqs;
        ATH_PCU_UNLOCK(sc);

        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        ATH_KTR(sc, ATH_KTR_TXCOMP, 1,
            "ath_tx_proc_q0: txqs=0x%08x", txqs);

        if (TXQACTIVE(txqs, 0) && ath_tx_processq(sc, &sc->sc_txq[0], 1))
                /* XXX why is lastrx updated in tx code? */
                sc->sc_lastrx = ath_hal_gettsf64(sc->sc_ah);
        if (TXQACTIVE(txqs, sc->sc_cabq->axq_qnum))
                ath_tx_processq(sc, sc->sc_cabq, 1);
#if 0
        /* remove, DragonFly uses OACTIVE to control if_start calls */
        IF_LOCK(&ifp->if_snd);
        ifq_clr_oactive(&ifp->if_snd);
        IF_UNLOCK(&ifp->if_snd);
#endif
        sc->sc_wd_timer = 0;

        if (sc->sc_softled)
                ath_led_event(sc, sc->sc_txrix);

        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt--;
        ATH_PCU_UNLOCK(sc);

        ath_power_restore_power_state(sc);

        ath_tx_kick(sc);
        wlan_serialize_exit();
}

/*
 * Deferred processing of transmit interrupt; special-cased
 * for four hardware queues, 0-3 (e.g. 5212 w/ WME support).
 */
static void
ath_tx_proc_q0123(void *arg, int npending)
{
        struct ath_softc *sc = arg;
#if 0
        struct ifnet *ifp = sc->sc_ifp;
#endif
        int nacked;
        uint32_t txqs;

        wlan_serialize_enter();
        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt++;
        txqs = sc->sc_txq_active;
        sc->sc_txq_active &= ~txqs;
        ATH_PCU_UNLOCK(sc);

        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        ATH_KTR(sc, ATH_KTR_TXCOMP, 1,
            "ath_tx_proc_q0123: txqs=0x%08x", txqs);

        /*
         * Process each active queue.
         */
        nacked = 0;
        if (TXQACTIVE(txqs, 0))
                nacked += ath_tx_processq(sc, &sc->sc_txq[0], 1);
        if (TXQACTIVE(txqs, 1))
                nacked += ath_tx_processq(sc, &sc->sc_txq[1], 1);
        if (TXQACTIVE(txqs, 2))
                nacked += ath_tx_processq(sc, &sc->sc_txq[2], 1);
        if (TXQACTIVE(txqs, 3))
                nacked += ath_tx_processq(sc, &sc->sc_txq[3], 1);
        if (TXQACTIVE(txqs, sc->sc_cabq->axq_qnum))
                ath_tx_processq(sc, sc->sc_cabq, 1);
        if (nacked)
                sc->sc_lastrx = ath_hal_gettsf64(sc->sc_ah);

#if 0
        /* remove, DragonFly uses OACTIVE to control if_start calls */
        IF_LOCK(&ifp->if_snd);
        ifq_clr_oactive(&ifp->if_snd);
        IF_UNLOCK(&ifp->if_snd);
#endif
        sc->sc_wd_timer = 0;

        if (sc->sc_softled)
                ath_led_event(sc, sc->sc_txrix);

        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt--;
        ATH_PCU_UNLOCK(sc);

        ath_power_restore_power_state(sc);

        ath_tx_kick(sc);
        wlan_serialize_exit();
}

/*
 * Deferred processing of transmit interrupt.
 */
static void
ath_tx_proc(void *arg, int npending)
{
        struct ath_softc *sc = arg;
#if 0
        struct ifnet *ifp = sc->sc_ifp;
#endif
        int i, nacked;
        uint32_t txqs;

        wlan_serialize_enter();
        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt++;
        txqs = sc->sc_txq_active;
        sc->sc_txq_active &= ~txqs;
        ATH_PCU_UNLOCK(sc);

        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        ATH_KTR(sc, ATH_KTR_TXCOMP, 1, "ath_tx_proc: txqs=0x%08x", txqs);

        /*
         * Process each active queue.
         */
        nacked = 0;
        for (i = 0; i < HAL_NUM_TX_QUEUES; i++)
                if (ATH_TXQ_SETUP(sc, i) && TXQACTIVE(txqs, i))
                        nacked += ath_tx_processq(sc, &sc->sc_txq[i], 1);
        if (nacked)
                sc->sc_lastrx = ath_hal_gettsf64(sc->sc_ah);

#if 0
        /* remove, DragonFly uses OACTIVE to control if_start calls */
        /* XXX check this inside of IF_LOCK? */
        IF_LOCK(&ifp->if_snd);
        ifq_clr_oactive(&ifp->if_snd);
        IF_UNLOCK(&ifp->if_snd);
#endif
        sc->sc_wd_timer = 0;

        if (sc->sc_softled)
                ath_led_event(sc, sc->sc_txrix);

        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt--;
        ATH_PCU_UNLOCK(sc);

        ath_power_restore_power_state(sc);

        ath_tx_kick(sc);
        wlan_serialize_exit();
}
#undef  TXQACTIVE

/*
 * Deferred processing of TXQ rescheduling.
 */
static void
ath_txq_sched_tasklet(void *arg, int npending)
{
        struct ath_softc *sc = arg;
        int i;

        wlan_serialize_enter();

        /* XXX is skipping ok? */
        ATH_PCU_LOCK(sc);
#if 0
        if (sc->sc_inreset_cnt > 0) {
                device_printf(sc->sc_dev,
                    "%s: sc_inreset_cnt > 0; skipping\n", __func__);
                ATH_PCU_UNLOCK(sc);
                wlan_serialize_exit();
                return;
        }
#endif
        sc->sc_txproc_cnt++;
        ATH_PCU_UNLOCK(sc);

        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        ATH_TX_LOCK(sc);
        for (i = 0; i < HAL_NUM_TX_QUEUES; i++) {
                if (ATH_TXQ_SETUP(sc, i)) {
                        ath_txq_sched(sc, &sc->sc_txq[i]);
                }
        }
        ATH_TX_UNLOCK(sc);

        ath_power_restore_power_state(sc);

        ATH_PCU_LOCK(sc);
        sc->sc_txproc_cnt--;
        ATH_PCU_UNLOCK(sc);
        wlan_serialize_exit();
}

void
ath_returnbuf_tail(struct ath_softc *sc, struct ath_buf *bf)
{

        ATH_TXBUF_LOCK_ASSERT(sc);

        if (bf->bf_flags & ATH_BUF_MGMT)
                TAILQ_INSERT_TAIL(&sc->sc_txbuf_mgmt, bf, bf_list);
        else {
                TAILQ_INSERT_TAIL(&sc->sc_txbuf, bf, bf_list);
                sc->sc_txbuf_cnt++;
                if (sc->sc_txbuf_cnt > ath_txbuf) {
                        device_printf(sc->sc_dev,
                            "%s: sc_txbuf_cnt > %d?\n",
                            __func__,
                            ath_txbuf);
                        sc->sc_txbuf_cnt = ath_txbuf;
                }
        }
}

void
ath_returnbuf_head(struct ath_softc *sc, struct ath_buf *bf)
{

        ATH_TXBUF_LOCK_ASSERT(sc);

        if (bf->bf_flags & ATH_BUF_MGMT)
                TAILQ_INSERT_HEAD(&sc->sc_txbuf_mgmt, bf, bf_list);
        else {
                TAILQ_INSERT_HEAD(&sc->sc_txbuf, bf, bf_list);
                sc->sc_txbuf_cnt++;
                if (sc->sc_txbuf_cnt > ATH_TXBUF) {
                        device_printf(sc->sc_dev,
                            "%s: sc_txbuf_cnt > %d?\n",
                            __func__,
                            ATH_TXBUF);
                        sc->sc_txbuf_cnt = ATH_TXBUF;
                }
        }
}

/*
 * Free the holding buffer if it exists
 */
void
ath_txq_freeholdingbuf(struct ath_softc *sc, struct ath_txq *txq)
{
        ATH_TXBUF_UNLOCK_ASSERT(sc);
        ATH_TXQ_LOCK_ASSERT(txq);

        if (txq->axq_holdingbf == NULL)
                return;

        txq->axq_holdingbf->bf_flags &= ~ATH_BUF_BUSY;

        ATH_TXBUF_LOCK(sc);
        ath_returnbuf_tail(sc, txq->axq_holdingbf);
        ATH_TXBUF_UNLOCK(sc);

        txq->axq_holdingbf = NULL;
}

/*
 * Add this buffer to the holding queue, freeing the previous
 * one if it exists.
 */
static void
ath_txq_addholdingbuf(struct ath_softc *sc, struct ath_buf *bf)
{
        struct ath_txq *txq;

        txq = &sc->sc_txq[bf->bf_state.bfs_tx_queue];

        ATH_TXBUF_UNLOCK_ASSERT(sc);
        ATH_TXQ_LOCK_ASSERT(txq);

        /* XXX assert ATH_BUF_BUSY is set */

        /* XXX assert the tx queue is under the max number */
        if (bf->bf_state.bfs_tx_queue > HAL_NUM_TX_QUEUES) {
                device_printf(sc->sc_dev, "%s: bf=%p: invalid tx queue (%d)\n",
                    __func__,
                    bf,
                    bf->bf_state.bfs_tx_queue);
                bf->bf_flags &= ~ATH_BUF_BUSY;
                ath_returnbuf_tail(sc, bf);
                return;
        }
        ath_txq_freeholdingbuf(sc, txq);
        txq->axq_holdingbf = bf;
}

/*
 * Return a buffer to the pool and update the 'busy' flag on the
 * previous 'tail' entry.
 *
 * This _must_ only be called when the buffer is involved in a completed
 * TX. The logic is that if it was part of an active TX, the previous
 * buffer on the list is now not involved in a halted TX DMA queue, waiting
 * for restart (eg for TDMA.)
 *
 * The caller must free the mbuf and recycle the node reference.
 *
 * XXX This method of handling busy / holding buffers is insanely stupid.
 * It requires bf_state.bfs_tx_queue to be correctly assigned.  It would
 * be much nicer if buffers in the processq() methods would instead be
 * always completed there (pushed onto a txq or ath_bufhead) so we knew
 * exactly what hardware queue they came from in the first place.
 */
void
ath_freebuf(struct ath_softc *sc, struct ath_buf *bf)
{
        struct ath_txq *txq;

        txq = &sc->sc_txq[bf->bf_state.bfs_tx_queue];

        KASSERT((bf->bf_node == NULL), ("%s: bf->bf_node != NULL\n", __func__));
        KASSERT((bf->bf_m == NULL), ("%s: bf->bf_m != NULL\n", __func__));

        /*
         * If this buffer is busy, push it onto the holding queue.
         */
        if (bf->bf_flags & ATH_BUF_BUSY) {
                ATH_TXQ_LOCK(txq);
                ath_txq_addholdingbuf(sc, bf);
                ATH_TXQ_UNLOCK(txq);
                return;
        }

        /*
         * Not a busy buffer, so free normally
         */
        ATH_TXBUF_LOCK(sc);
        ath_returnbuf_tail(sc, bf);
        ATH_TXBUF_UNLOCK(sc);
}

/*
 * This is currently used by ath_tx_draintxq() and
 * ath_tx_tid_free_pkts().
 *
 * It recycles a single ath_buf.
 */
void
ath_tx_freebuf(struct ath_softc *sc, struct ath_buf *bf, int status)
{
        struct ieee80211_node *ni = bf->bf_node;
        struct mbuf *m0 = bf->bf_m;

        /*
         * Make sure that we only sync/unload if there's an mbuf.
         * If not (eg we cloned a buffer), the unload will have already
         * occured.
         */
        if (bf->bf_m != NULL) {
                bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
                    BUS_DMASYNC_POSTWRITE);
                bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
        }

        bf->bf_node = NULL;
        bf->bf_m = NULL;

        /* Free the buffer, it's not needed any longer */
        ath_freebuf(sc, bf);

        /* Pass the buffer back to net80211 - completing it */
        ieee80211_tx_complete(ni, m0, status);
}

static struct ath_buf *
ath_tx_draintxq_get_one(struct ath_softc *sc, struct ath_txq *txq)
{
        struct ath_buf *bf;

        ATH_TXQ_LOCK_ASSERT(txq);

        /*
         * Drain the FIFO queue first, then if it's
         * empty, move to the normal frame queue.
         */
        bf = TAILQ_FIRST(&txq->fifo.axq_q);
        if (bf != NULL) {
                /*
                 * Is it the last buffer in this set?
                 * Decrement the FIFO counter.
                 */
                if (bf->bf_flags & ATH_BUF_FIFOEND) {
                        if (txq->axq_fifo_depth == 0) {
                                device_printf(sc->sc_dev,
                                    "%s: Q%d: fifo_depth=0, fifo.axq_depth=%d?\n",
                                    __func__,
                                    txq->axq_qnum,
                                    txq->fifo.axq_depth);
                        } else
                                txq->axq_fifo_depth--;
                }
                ATH_TXQ_REMOVE(&txq->fifo, bf, bf_list);
                return (bf);
        }

        /*
         * Debugging!
         */
        if (txq->axq_fifo_depth != 0 || txq->fifo.axq_depth != 0) {
                device_printf(sc->sc_dev,
                    "%s: Q%d: fifo_depth=%d, fifo.axq_depth=%d\n",
                    __func__,
                    txq->axq_qnum,
                    txq->axq_fifo_depth,
                    txq->fifo.axq_depth);
        }

        /*
         * Now drain the pending queue.
         */
        bf = TAILQ_FIRST(&txq->axq_q);
        if (bf == NULL) {
                txq->axq_link = NULL;
                return (NULL);
        }
        ATH_TXQ_REMOVE(txq, bf, bf_list);
        return (bf);
}

void
ath_tx_draintxq(struct ath_softc *sc, struct ath_txq *txq)
{
#ifdef ATH_DEBUG
        struct ath_hal *ah = sc->sc_ah;
#endif
        struct ath_buf *bf;
        u_int ix;

        /*
         * NB: this assumes output has been stopped and
         *     we do not need to block ath_tx_proc
         */
        for (ix = 0;; ix++) {
                ATH_TXQ_LOCK(txq);
                bf = ath_tx_draintxq_get_one(sc, txq);
                if (bf == NULL) {
                        ATH_TXQ_UNLOCK(txq);
                        break;
                }
                if (bf->bf_state.bfs_aggr)
                        txq->axq_aggr_depth--;
#ifdef ATH_DEBUG
                if (sc->sc_debug & ATH_DEBUG_RESET) {
                        struct ieee80211com *ic = sc->sc_ifp->if_l2com;
                        int status = 0;

                        /*
                         * EDMA operation has a TX completion FIFO
                         * separate from the TX descriptor, so this
                         * method of checking the "completion" status
                         * is wrong.
                         */
                        if (! sc->sc_isedma) {
                                status = (ath_hal_txprocdesc(ah,
                                    bf->bf_lastds,
                                    &bf->bf_status.ds_txstat) == HAL_OK);
                        }
                        ath_printtxbuf(sc, bf, txq->axq_qnum, ix, status);
                        ieee80211_dump_pkt(ic, mtod(bf->bf_m, const uint8_t *),
                            bf->bf_m->m_len, 0, -1);
                }
#endif /* ATH_DEBUG */
                /*
                 * Since we're now doing magic in the completion
                 * functions, we -must- call it for aggregation
                 * destinations or BAW tracking will get upset.
                 */
                /*
                 * Clear ATH_BUF_BUSY; the completion handler
                 * will free the buffer.
                 */
                ATH_TXQ_UNLOCK(txq);
                bf->bf_flags &= ~ATH_BUF_BUSY;
                if (bf->bf_comp)
                        bf->bf_comp(sc, bf, 1);
                else
                        ath_tx_default_comp(sc, bf, 1);
        }

        /*
         * Free the holding buffer if it exists
         */
        ATH_TXQ_LOCK(txq);
        ath_txq_freeholdingbuf(sc, txq);
        ATH_TXQ_UNLOCK(txq);

        /*
         * Drain software queued frames which are on
         * active TIDs.
         */
        ath_tx_txq_drain(sc, txq);
}

static void
ath_tx_stopdma(struct ath_softc *sc, struct ath_txq *txq)
{
        struct ath_hal *ah = sc->sc_ah;

        ATH_TXQ_LOCK_ASSERT(txq);

        DPRINTF(sc, ATH_DEBUG_RESET,
            "%s: tx queue [%u] %p, active=%d, hwpending=%d, flags 0x%08x, "
            "link %p, holdingbf=%p\n",
            __func__,
            txq->axq_qnum,
            (caddr_t)(uintptr_t) ath_hal_gettxbuf(ah, txq->axq_qnum),
            (int) (!! ath_hal_txqenabled(ah, txq->axq_qnum)),
            (int) ath_hal_numtxpending(ah, txq->axq_qnum),
            txq->axq_flags,
            txq->axq_link,
            txq->axq_holdingbf);

        (void) ath_hal_stoptxdma(ah, txq->axq_qnum);
        /* We've stopped TX DMA, so mark this as stopped. */
        txq->axq_flags &= ~ATH_TXQ_PUTRUNNING;

#ifdef  ATH_DEBUG
        if ((sc->sc_debug & ATH_DEBUG_RESET)
            && (txq->axq_holdingbf != NULL)) {
                ath_printtxbuf(sc, txq->axq_holdingbf, txq->axq_qnum, 0, 0);
        }
#endif
}

int
ath_stoptxdma(struct ath_softc *sc)
{
        struct ath_hal *ah = sc->sc_ah;
        int i;

        /* XXX return value */
        if (sc->sc_invalid)
                return 0;

        if (!sc->sc_invalid) {
                /* don't touch the hardware if marked invalid */
                DPRINTF(sc, ATH_DEBUG_RESET, "%s: tx queue [%u] %p, link %p\n",
                    __func__, sc->sc_bhalq,
                    (caddr_t)(uintptr_t) ath_hal_gettxbuf(ah, sc->sc_bhalq),
                    NULL);

                /* stop the beacon queue */
                (void) ath_hal_stoptxdma(ah, sc->sc_bhalq);

                /* Stop the data queues */
                for (i = 0; i < HAL_NUM_TX_QUEUES; i++) {
                        if (ATH_TXQ_SETUP(sc, i)) {
                                ATH_TXQ_LOCK(&sc->sc_txq[i]);
                                ath_tx_stopdma(sc, &sc->sc_txq[i]);
                                ATH_TXQ_UNLOCK(&sc->sc_txq[i]);
                        }
                }
        }

        return 1;
}

#ifdef  ATH_DEBUG
void
ath_tx_dump(struct ath_softc *sc, struct ath_txq *txq)
{
        struct ath_hal *ah = sc->sc_ah;
        struct ath_buf *bf;
        int i = 0;

        if (! (sc->sc_debug & ATH_DEBUG_RESET))
                return;

        device_printf(sc->sc_dev, "%s: Q%d: begin\n",
            __func__, txq->axq_qnum);
        TAILQ_FOREACH(bf, &txq->axq_q, bf_list) {
                ath_printtxbuf(sc, bf, txq->axq_qnum, i,
                        ath_hal_txprocdesc(ah, bf->bf_lastds,
                            &bf->bf_status.ds_txstat) == HAL_OK);
                i++;
        }
        device_printf(sc->sc_dev, "%s: Q%d: end\n",
            __func__, txq->axq_qnum);
}
#endif /* ATH_DEBUG */

/*
 * Drain the transmit queues and reclaim resources.
 */
void
ath_legacy_tx_drain(struct ath_softc *sc, ATH_RESET_TYPE reset_type)
{
        struct ath_hal *ah = sc->sc_ah;
#ifdef ATH_DEBUG
        struct ifnet *ifp = sc->sc_ifp;
#endif
        int i;
        struct ath_buf *bf_last;

        (void) ath_stoptxdma(sc);

        /*
         * Dump the queue contents
         */
        for (i = 0; i < HAL_NUM_TX_QUEUES; i++) {
                /*
                 * XXX TODO: should we just handle the completed TX frames
                 * here, whether or not the reset is a full one or not?
                 */
                if (ATH_TXQ_SETUP(sc, i)) {
#ifdef  ATH_DEBUG
                        if (sc->sc_debug & ATH_DEBUG_RESET)
                                ath_tx_dump(sc, &sc->sc_txq[i]);
#endif  /* ATH_DEBUG */
                        if (reset_type == ATH_RESET_NOLOSS) {
                                ath_tx_processq(sc, &sc->sc_txq[i], 0);
                                ATH_TXQ_LOCK(&sc->sc_txq[i]);
                                /*
                                 * Free the holding buffer; DMA is now
                                 * stopped.
                                 */
                                ath_txq_freeholdingbuf(sc, &sc->sc_txq[i]);
                                /*
                                 * Setup the link pointer to be the
                                 * _last_ buffer/descriptor in the list.
                                 * If there's nothing in the list, set it
                                 * to NULL.
                                 */
                                bf_last = ATH_TXQ_LAST(&sc->sc_txq[i],
                                    axq_q_s);
                                if (bf_last != NULL) {
                                        ath_hal_gettxdesclinkptr(ah,
                                            bf_last->bf_lastds,
                                            &sc->sc_txq[i].axq_link);
                                } else {
                                        sc->sc_txq[i].axq_link = NULL;
                                }
                                ATH_TXQ_UNLOCK(&sc->sc_txq[i]);
                        } else
                                ath_tx_draintxq(sc, &sc->sc_txq[i]);
                }
        }
#ifdef ATH_DEBUG
        if (sc->sc_debug & ATH_DEBUG_RESET) {
                struct ath_buf *bf = TAILQ_FIRST(&sc->sc_bbuf);
                if (bf != NULL && bf->bf_m != NULL) {
                        ath_printtxbuf(sc, bf, sc->sc_bhalq, 0,
                                ath_hal_txprocdesc(ah, bf->bf_lastds,
                                    &bf->bf_status.ds_txstat) == HAL_OK);
                        ieee80211_dump_pkt(ifp->if_l2com,
                            mtod(bf->bf_m, const uint8_t *), bf->bf_m->m_len,
                            0, -1);
                }
        }
#endif /* ATH_DEBUG */
#if 0
        /* remove, DragonFly uses OACTIVE to control if_start calls */
        IF_LOCK(&ifp->if_snd);
        ifq_clr_oactive(&ifp->if_snd);
        IF_UNLOCK(&ifp->if_snd);
#endif
        sc->sc_wd_timer = 0;
}

/*
 * Update internal state after a channel change.
 */
static void
ath_chan_change(struct ath_softc *sc, struct ieee80211_channel *chan)
{
        enum ieee80211_phymode mode;

        /*
         * Change channels and update the h/w rate map
         * if we're switching; e.g. 11a to 11b/g.
         */
        mode = ieee80211_chan2mode(chan);
        if (mode != sc->sc_curmode)
                ath_setcurmode(sc, mode);
        sc->sc_curchan = chan;
}

/*
 * Set/change channels.  If the channel is really being changed,
 * it's done by resetting the chip.  To accomplish this we must
 * first cleanup any pending DMA, then restart stuff after a la
 * ath_init.
 */
static int
ath_chan_set(struct ath_softc *sc, struct ieee80211_channel *chan)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        int ret = 0;

        /* Treat this as an interface reset */
        ATH_PCU_UNLOCK_ASSERT(sc);
        ATH_UNLOCK_ASSERT(sc);

        /* (Try to) stop TX/RX from occuring */
        taskqueue_block(sc->sc_tq);

        ATH_PCU_LOCK(sc);

        /* Stop new RX/TX/interrupt completion */
        if (ath_reset_grablock(sc, 1) == 0) {
                device_printf(sc->sc_dev, "%s: concurrent reset! Danger!\n",
                    __func__);
        }

        ath_hal_intrset(ah, 0);

        /* Stop pending RX/TX completion */
        ath_txrx_stop_locked(sc);

        ATH_PCU_UNLOCK(sc);

        DPRINTF(sc, ATH_DEBUG_RESET, "%s: %u (%u MHz, flags 0x%x)\n",
            __func__, ieee80211_chan2ieee(ic, chan),
            chan->ic_freq, chan->ic_flags);
        if (chan != sc->sc_curchan) {
                HAL_STATUS status;
                /*
                 * To switch channels clear any pending DMA operations;
                 * wait long enough for the RX fifo to drain, reset the
                 * hardware at the new frequency, and then re-enable
                 * the relevant bits of the h/w.
                 */
#if 0
                ath_hal_intrset(ah, 0);         /* disable interrupts */
#endif
                ath_stoprecv(sc, 1);            /* turn off frame recv */
                /*
                 * First, handle completed TX/RX frames.
                 */
                ath_rx_flush(sc);
                ath_draintxq(sc, ATH_RESET_NOLOSS);
                /*
                 * Next, flush the non-scheduled frames.
                 */
                ath_draintxq(sc, ATH_RESET_FULL);       /* clear pending tx frames */

                ath_update_chainmasks(sc, chan);
                ath_hal_setchainmasks(sc->sc_ah, sc->sc_cur_txchainmask,
                    sc->sc_cur_rxchainmask);
                sc->sc_rxfifo_state = ATH_RXFIFO_RESET;
                if (!ath_hal_reset(ah, sc->sc_opmode, chan, AH_TRUE, &status)) {
                        if_printf(ifp, "%s: unable to reset "
                            "channel %u (%u MHz, flags 0x%x), hal status %u\n",
                            __func__, ieee80211_chan2ieee(ic, chan),
                            chan->ic_freq, chan->ic_flags, status);
                        ret = EIO;
                        goto finish;
                }
                sc->sc_diversity = ath_hal_getdiversity(ah);

                /* Let DFS at it in case it's a DFS channel */
                ath_dfs_radar_enable(sc, chan);

                /* Let spectral at in case spectral is enabled */
                ath_spectral_enable(sc, chan);

                /*
                 * Let bluetooth coexistence at in case it's needed for this
                 * channel
                 */
                ath_btcoex_enable(sc, ic->ic_curchan);

                /*
                 * If we're doing TDMA, enforce the TXOP limitation for chips
                 * that support it.
                 */
                if (sc->sc_hasenforcetxop && sc->sc_tdma)
                        ath_hal_setenforcetxop(sc->sc_ah, 1);
                else
                        ath_hal_setenforcetxop(sc->sc_ah, 0);

                /*
                 * Re-enable rx framework.
                 */
                if (ath_startrecv(sc) != 0) {
                        if_printf(ifp, "%s: unable to restart recv logic\n",
                            __func__);
                        ret = EIO;
                        goto finish;
                }

                /*
                 * Change channels and update the h/w rate map
                 * if we're switching; e.g. 11a to 11b/g.
                 */
                ath_chan_change(sc, chan);

                /*
                 * Reset clears the beacon timers; reset them
                 * here if needed.
                 */
                if (sc->sc_beacons) {           /* restart beacons */
#ifdef IEEE80211_SUPPORT_TDMA
                        if (sc->sc_tdma)
                                ath_tdma_config(sc, NULL);
                        else
#endif
                        ath_beacon_config(sc, NULL);
                }

                /*
                 * Re-enable interrupts.
                 */
#if 0
                ath_hal_intrset(ah, sc->sc_imask);
#endif
        }

finish:
        ATH_PCU_LOCK(sc);
        sc->sc_inreset_cnt--;
        /* XXX only do this if sc_inreset_cnt == 0? */
        ath_hal_intrset(ah, sc->sc_imask);
        ATH_PCU_UNLOCK(sc);

#if 0
        /* remove, DragonFly uses OACTIVE to control if_start calls */
        IF_LOCK(&ifp->if_snd);
        ifq_clr_oactive(&ifp->if_snd);
        IF_UNLOCK(&ifp->if_snd);
#endif
        ath_txrx_start(sc);
        /* XXX ath_start? */

        return ret;
}

/*
 * Periodically recalibrate the PHY to account
 * for temperature/environment changes.
 */
static void
ath_calibrate(void *arg)
{
        struct ath_softc *sc = arg;
        struct ath_hal *ah = sc->sc_ah;
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        HAL_BOOL longCal, isCalDone = AH_TRUE;
        HAL_BOOL aniCal, shortCal = AH_FALSE;
        int nextcal;

        /*
         * Force the hardware awake for ANI work.
         */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        wlan_serialize_enter();

        /* Skip trying to do this if we're in reset */
        if (sc->sc_inreset_cnt)
                goto restart;
        if (ic->ic_flags & IEEE80211_F_SCAN)    /* defer, off channel */
                goto restart;
        longCal = (ticks - sc->sc_lastlongcal >= ath_longcalinterval*hz);
        aniCal = (ticks - sc->sc_lastani >= ath_anicalinterval*hz/1000);
        if (sc->sc_doresetcal)
                shortCal = (ticks - sc->sc_lastshortcal >= ath_shortcalinterval*hz/1000);

        DPRINTF(sc, ATH_DEBUG_CALIBRATE, "%s: shortCal=%d; longCal=%d; aniCal=%d\n", __func__, shortCal, longCal, aniCal);
        if (aniCal) {
                sc->sc_stats.ast_ani_cal++;
                sc->sc_lastani = ticks;
                ath_hal_ani_poll(ah, sc->sc_curchan);
        }

        if (longCal) {
                sc->sc_stats.ast_per_cal++;
                sc->sc_lastlongcal = ticks;
                if (ath_hal_getrfgain(ah) == HAL_RFGAIN_NEED_CHANGE) {
                        /*
                         * Rfgain is out of bounds, reset the chip
                         * to load new gain values.
                         */
                        DPRINTF(sc, ATH_DEBUG_CALIBRATE,
                                "%s: rfgain change\n", __func__);
                        sc->sc_stats.ast_per_rfgain++;
                        sc->sc_resetcal = 0;
                        sc->sc_doresetcal = AH_TRUE;
                        taskqueue_enqueue(sc->sc_tq, &sc->sc_resettask);
                        callout_reset(&sc->sc_cal_ch, 1, ath_calibrate, sc);
                        goto done;
                }
                /*
                 * If this long cal is after an idle period, then
                 * reset the data collection state so we start fresh.
                 */
                if (sc->sc_resetcal) {
                        (void) ath_hal_calreset(ah, sc->sc_curchan);
                        sc->sc_lastcalreset = ticks;
                        sc->sc_lastshortcal = ticks;
                        sc->sc_resetcal = 0;
                        sc->sc_doresetcal = AH_TRUE;
                }
        }

        /* Only call if we're doing a short/long cal, not for ANI calibration */
        if (shortCal || longCal) {
                isCalDone = AH_FALSE;
                if (ath_hal_calibrateN(ah, sc->sc_curchan, longCal, &isCalDone)) {
                        if (longCal) {
                                /*
                                 * Calibrate noise floor data again in case of change.
                                 */
                                ath_hal_process_noisefloor(ah);
                        }
                } else {
                        DPRINTF(sc, ATH_DEBUG_ANY,
                                "%s: calibration of channel %u failed\n",
                                __func__, sc->sc_curchan->ic_freq);
                        sc->sc_stats.ast_per_calfail++;
                }
                if (shortCal)
                        sc->sc_lastshortcal = ticks;
        }
        if (!isCalDone) {
restart:
                /*
                 * Use a shorter interval to potentially collect multiple
                 * data samples required to complete calibration.  Once
                 * we're told the work is done we drop back to a longer
                 * interval between requests.  We're more aggressive doing
                 * work when operating as an AP to improve operation right
                 * after startup.
                 */
                sc->sc_lastshortcal = ticks;
                nextcal = ath_shortcalinterval*hz/1000;
                if (sc->sc_opmode != HAL_M_HOSTAP)
                        nextcal *= 10;
                sc->sc_doresetcal = AH_TRUE;
        } else {
                /* nextcal should be the shortest time for next event */
                nextcal = ath_longcalinterval*hz;
                if (sc->sc_lastcalreset == 0)
                        sc->sc_lastcalreset = sc->sc_lastlongcal;
                else if (ticks - sc->sc_lastcalreset >= ath_resetcalinterval*hz)
                        sc->sc_resetcal = 1;    /* setup reset next trip */
                sc->sc_doresetcal = AH_FALSE;
        }
        /* ANI calibration may occur more often than short/long/resetcal */
        if (ath_anicalinterval > 0)
                nextcal = MIN(nextcal, ath_anicalinterval*hz/1000);

        if (nextcal != 0) {
                DPRINTF(sc, ATH_DEBUG_CALIBRATE, "%s: next +%u (%sisCalDone)\n",
                    __func__, nextcal, isCalDone ? "" : "!");
                callout_reset(&sc->sc_cal_ch, nextcal, ath_calibrate, sc);
        } else {
                DPRINTF(sc, ATH_DEBUG_CALIBRATE, "%s: calibration disabled\n",
                    __func__);
                /* NB: don't rearm timer */
        }
done:
        /*
         * Restore power state now that we're done.
         */
        ath_power_restore_power_state(sc);
        wlan_serialize_exit();
}

static void
ath_scan_start(struct ieee80211com *ic)
{
        struct ifnet *ifp = ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;
        u_int32_t rfilt;

        /* XXX calibration timer? */

        ATH_LOCK(sc);
        sc->sc_scanning = 1;
        sc->sc_syncbeacon = 0;
        rfilt = ath_calcrxfilter(sc);
        ATH_UNLOCK(sc);

        ATH_PCU_LOCK(sc);
        ath_hal_setrxfilter(ah, rfilt);
        ath_hal_setassocid(ah, ifp->if_broadcastaddr, 0);
        ATH_PCU_UNLOCK(sc);

        DPRINTF(sc, ATH_DEBUG_STATE, "%s: RX filter 0x%x bssid %s aid 0\n",
                 __func__, rfilt, ath_hal_ether_sprintf(ifp->if_broadcastaddr));
}

static void
ath_scan_end(struct ieee80211com *ic)
{
        struct ifnet *ifp = ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;
        u_int32_t rfilt;

        ATH_LOCK(sc);
        sc->sc_scanning = 0;
        rfilt = ath_calcrxfilter(sc);
        ATH_UNLOCK(sc);

        ATH_PCU_LOCK(sc);
        ath_hal_setrxfilter(ah, rfilt);
        ath_hal_setassocid(ah, sc->sc_curbssid, sc->sc_curaid);

        ath_hal_process_noisefloor(ah);
        ATH_PCU_UNLOCK(sc);

        DPRINTF(sc, ATH_DEBUG_STATE, "%s: RX filter 0x%x bssid %s aid 0x%x\n",
                 __func__, rfilt, ath_hal_ether_sprintf(sc->sc_curbssid),
                 sc->sc_curaid);
}

#ifdef  ATH_ENABLE_11N
/*
 * For now, just do a channel change.
 *
 * Later, we'll go through the hard slog of suspending tx/rx, changing rate
 * control state and resetting the hardware without dropping frames out
 * of the queue.
 *
 * The unfortunate trouble here is making absolutely sure that the
 * channel width change has propagated enough so the hardware
 * absolutely isn't handed bogus frames for it's current operating
 * mode. (Eg, 40MHz frames in 20MHz mode.) Since TX and RX can and
 * does occur in parallel, we need to make certain we've blocked
 * any further ongoing TX (and RX, that can cause raw TX)
 * before we do this.
 */
static void
ath_update_chw(struct ieee80211com *ic)
{
        struct ifnet *ifp = ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;

        DPRINTF(sc, ATH_DEBUG_STATE, "%s: called\n", __func__);
        ath_set_channel(ic);
}
#endif  /* ATH_ENABLE_11N */

static void
ath_set_channel(struct ieee80211com *ic)
{
        struct ifnet *ifp = ic->ic_ifp;
        struct ath_softc *sc = ifp->if_softc;

        (void) ath_chan_set(sc, ic->ic_curchan);
        /*
         * If we are returning to our bss channel then mark state
         * so the next recv'd beacon's tsf will be used to sync the
         * beacon timers.  Note that since we only hear beacons in
         * sta/ibss mode this has no effect in other operating modes.
         */
        ATH_LOCK(sc);
        ath_power_set_power_state(sc, HAL_PM_AWAKE);
        if (!sc->sc_scanning && ic->ic_curchan == ic->ic_bsschan)
                sc->sc_syncbeacon = 1;
        ath_power_restore_power_state(sc);
        ATH_UNLOCK(sc);
}

/*
 * Walk the vap list and check if there any vap's in RUN state.
 */
static int
ath_isanyrunningvaps(struct ieee80211vap *this)
{
        struct ieee80211com *ic = this->iv_ic;
        struct ieee80211vap *vap;

        IEEE80211_LOCK_ASSERT(ic);

        TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
                if (vap != this && vap->iv_state >= IEEE80211_S_RUN)
                        return 1;
        }
        return 0;
}

static int
ath_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_vap *avp = ATH_VAP(vap);
        struct ath_hal *ah = sc->sc_ah;
        struct ieee80211_node *ni = NULL;
        int i, error, stamode;
        u_int32_t rfilt;
        int csa_run_transition = 0;
        enum ieee80211_state ostate = vap->iv_state;

        static const HAL_LED_STATE leds[] = {
            HAL_LED_INIT,       /* IEEE80211_S_INIT */
            HAL_LED_SCAN,       /* IEEE80211_S_SCAN */
            HAL_LED_AUTH,       /* IEEE80211_S_AUTH */
            HAL_LED_ASSOC,      /* IEEE80211_S_ASSOC */
            HAL_LED_RUN,        /* IEEE80211_S_CAC */
            HAL_LED_RUN,        /* IEEE80211_S_RUN */
            HAL_LED_RUN,        /* IEEE80211_S_CSA */
            HAL_LED_RUN,        /* IEEE80211_S_SLEEP */
        };

        DPRINTF(sc, ATH_DEBUG_STATE, "%s: %s -> %s\n", __func__,
                ieee80211_state_name[ostate],
                ieee80211_state_name[nstate]);

        /*
         * net80211 _should_ have the comlock asserted at this point.
         * There are some comments around the calls to vap->iv_newstate
         * which indicate that it (newstate) may end up dropping the
         * lock.  This and the subsequent lock assert check after newstate
         * are an attempt to catch these and figure out how/why.
         */
        IEEE80211_LOCK_ASSERT(ic);

        /* Before we touch the hardware - wake it up */
        /*
         * If the NIC is in anything other than SLEEP state,
         * we need to ensure that self-generated frames are
         * set for PWRMGT=0.  Otherwise we may end up with
         * strange situations.
         *
         * XXX TODO: is this actually the case? :-)
         */
        if (nstate != IEEE80211_S_SLEEP)
                ath_power_setselfgen(sc, HAL_PM_AWAKE);

        /*
         * Now, wake the thing up.
         */
        ath_power_set_power_state(sc, HAL_PM_AWAKE);

        if (ostate == IEEE80211_S_CSA && nstate == IEEE80211_S_RUN)
                csa_run_transition = 1;

        wlan_serialize_exit();
        callout_stop_sync(&sc->sc_cal_ch);
        wlan_serialize_enter();
        ath_hal_setledstate(ah, leds[nstate]);  /* set LED */

        if (nstate == IEEE80211_S_SCAN) {
                /*
                 * Scanning: turn off beacon miss and don't beacon.
                 * Mark beacon state so when we reach RUN state we'll
                 * [re]setup beacons.  Unblock the task q thread so
                 * deferred interrupt processing is done.
                 */

                /* Ensure we stay awake during scan */
                ath_power_setselfgen(sc, HAL_PM_AWAKE);
                ath_power_setpower(sc, HAL_PM_AWAKE);

                ath_hal_intrset(ah,
                    sc->sc_imask &~ (HAL_INT_SWBA | HAL_INT_BMISS));
                sc->sc_imask &= ~(HAL_INT_SWBA | HAL_INT_BMISS);
                sc->sc_beacons = 0;
                taskqueue_unblock(sc->sc_tq);
        }

        ni = ieee80211_ref_node(vap->iv_bss);
        rfilt = ath_calcrxfilter(sc);
        stamode = (vap->iv_opmode == IEEE80211_M_STA ||
                   vap->iv_opmode == IEEE80211_M_AHDEMO ||
                   vap->iv_opmode == IEEE80211_M_IBSS);

        /*
         * XXX Dont need to do this (and others) if we've transitioned
         * from SLEEP->RUN.
         */
        if (stamode && nstate == IEEE80211_S_RUN) {
                sc->sc_curaid = ni->ni_associd;
                IEEE80211_ADDR_COPY(sc->sc_curbssid, ni->ni_bssid);
                ath_hal_setassocid(ah, sc->sc_curbssid, sc->sc_curaid);
        }
        DPRINTF(sc, ATH_DEBUG_STATE, "%s: RX filter 0x%x bssid %s aid 0x%x\n",
           __func__, rfilt,
           ath_hal_ether_sprintf(sc->sc_curbssid), sc->sc_curaid);
        ath_hal_setrxfilter(ah, rfilt);

        /* XXX is this to restore keycache on resume? */
        if (vap->iv_opmode != IEEE80211_M_STA &&
            (vap->iv_flags & IEEE80211_F_PRIVACY)) {
                for (i = 0; i < IEEE80211_WEP_NKID; i++)
                        if (ath_hal_keyisvalid(ah, i))
                                ath_hal_keysetmac(ah, i, ni->ni_bssid);
        }

        /*
         * Invoke the parent method to do net80211 work.
         */
        error = avp->av_newstate(vap, nstate, arg);
        if (error != 0)
                goto bad;

        /*
         * See above: ensure av_newstate() doesn't drop the lock
         * on us.
         */
        IEEE80211_LOCK_ASSERT(ic);

        if (nstate == IEEE80211_S_RUN) {
                /* NB: collect bss node again, it may have changed */
                ieee80211_free_node(ni);
                ni = ieee80211_ref_node(vap->iv_bss);

                DPRINTF(sc, ATH_DEBUG_STATE,
                    "%s(RUN): iv_flags 0x%08x bintvl %d bssid %s "
                    "capinfo 0x%04x chan %d\n", __func__,
                    vap->iv_flags, ni->ni_intval,
                    ath_hal_ether_sprintf(ni->ni_bssid),
                    ni->ni_capinfo, ieee80211_chan2ieee(ic, ic->ic_curchan));

                switch (vap->iv_opmode) {
#ifdef IEEE80211_SUPPORT_TDMA
                case IEEE80211_M_AHDEMO:
                        if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
                                break;
                        /* fall thru... */
#endif
                case IEEE80211_M_HOSTAP:
                case IEEE80211_M_IBSS:
                case IEEE80211_M_MBSS:
                        /*
                         * Allocate and setup the beacon frame.
                         *
                         * Stop any previous beacon DMA.  This may be
                         * necessary, for example, when an ibss merge
                         * causes reconfiguration; there will be a state
                         * transition from RUN->RUN that means we may
                         * be called with beacon transmission active.
                         */
                        ath_hal_stoptxdma(ah, sc->sc_bhalq);

                        error = ath_beacon_alloc(sc, ni);
                        if (error != 0)
                                goto bad;
                        /*
                         * If joining an adhoc network defer beacon timer
                         * configuration to the next beacon frame so we
                         * have a current TSF to use.  Otherwise we're
                         * starting an ibss/bss so there's no need to delay;
                         * if this is the first vap moving to RUN state, then
                         * beacon state needs to be [re]configured.
                         */
                        if (vap->iv_opmode == IEEE80211_M_IBSS &&
                            ni->ni_tstamp.tsf != 0) {
                                sc->sc_syncbeacon = 1;
                        } else if (!sc->sc_beacons) {
#ifdef IEEE80211_SUPPORT_TDMA
                                if (vap->iv_caps & IEEE80211_C_TDMA)
                                        ath_tdma_config(sc, vap);
                                else
#endif
                                        ath_beacon_config(sc, vap);
                                sc->sc_beacons = 1;
                        }
                        break;
                case IEEE80211_M_STA:
                        /*
                         * Defer beacon timer configuration to the next
                         * beacon frame so we have a current TSF to use
                         * (any TSF collected when scanning is likely old).
                         * However if it's due to a CSA -> RUN transition,
                         * force a beacon update so we pick up a lack of
                         * beacons from an AP in CAC and thus force a
                         * scan.
                         *
                         * And, there's also corner cases here where
                         * after a scan, the AP may have disappeared.
                         * In that case, we may not receive an actual
                         * beacon to update the beacon timer and thus we
                         * won't get notified of the missing beacons.
                         */
                        if (ostate != IEEE80211_S_RUN &&
                            ostate != IEEE80211_S_SLEEP) {
                                DPRINTF(sc, ATH_DEBUG_BEACON,
                                        "%s: STA; syncbeacon=1\n", __func__);
                                sc->sc_syncbeacon = 1;

                                if (csa_run_transition)
                                        ath_beacon_config(sc, vap);

                                /*
                                 * PR: kern/175227
                                 *
                                 * Reconfigure beacons during reset; as
                                 * otherwise
                                 * we won't get the beacon timers reprogrammed
                                 * after a reset and thus we won't pick up a
                                 * beacon miss interrupt.
                                 *
                                 * Hopefully we'll see a beacon before the BMISS
                                 * timer fires (too often), leading to a STA
                                 * disassociation.
                                 */
                                sc->sc_beacons = 1;
                        }
                        break;
                case IEEE80211_M_MONITOR:
                        /*
                         * Monitor mode vaps have only INIT->RUN and RUN->RUN
                         * transitions so we must re-enable interrupts here to
                         * handle the case of a single monitor mode vap.
                         */
                        ath_hal_intrset(ah, sc->sc_imask);
                        break;
                case IEEE80211_M_WDS:
                        break;
                default:
                        break;
                }
                /*
                 * Let the hal process statistics collected during a
                 * scan so it can provide calibrated noise floor data.
                 */
                ath_hal_process_noisefloor(ah);
                /*
                 * Reset rssi stats; maybe not the best place...
                 */
                sc->sc_halstats.ns_avgbrssi = ATH_RSSI_DUMMY_MARKER;
                sc->sc_halstats.ns_avgrssi = ATH_RSSI_DUMMY_MARKER;
                sc->sc_halstats.ns_avgtxrssi = ATH_RSSI_DUMMY_MARKER;

                /*
                 * Force awake for RUN mode
                 */
                ath_power_setselfgen(sc, HAL_PM_AWAKE);
                ath_power_setpower(sc, HAL_PM_AWAKE);

                /*
                 * Finally, start any timers and the task q thread
                 * (in case we didn't go through SCAN state).
                 */
                if (ath_longcalinterval != 0) {
                        /* start periodic recalibration timer */
                        callout_reset(&sc->sc_cal_ch, 1, ath_calibrate, sc);
                } else {
                        DPRINTF(sc, ATH_DEBUG_CALIBRATE,
                            "%s: calibration disabled\n", __func__);
                }

                taskqueue_unblock(sc->sc_tq);
        } else if (nstate == IEEE80211_S_INIT) {
                /*
                 * If there are no vaps left in RUN state then
                 * shutdown host/driver operation:
                 * o disable interrupts
                 * o disable the task queue thread
                 * o mark beacon processing as stopped
                 */
                if (!ath_isanyrunningvaps(vap)) {
                        sc->sc_imask &= ~(HAL_INT_SWBA | HAL_INT_BMISS);
                        /* disable interrupts  */
                        ath_hal_intrset(ah, sc->sc_imask &~ HAL_INT_GLOBAL);
                        taskqueue_block(sc->sc_tq);
                        sc->sc_beacons = 0;
                }
#ifdef IEEE80211_SUPPORT_TDMA
                ath_hal_setcca(ah, AH_TRUE);
#endif
        } else if (nstate == IEEE80211_S_SLEEP) {
                /* We're going to sleep, so transition appropriately */
                /* For now, only do this if we're a single STA vap */
                if (sc->sc_nvaps == 1 &&
                    vap->iv_opmode == IEEE80211_M_STA) {
                        DPRINTF(sc, ATH_DEBUG_BEACON,
                                "%s: syncbeacon=%d\n",
                                __func__, sc->sc_syncbeacon);
                        /*
                         * Always at least set the self-generated
                         * frame config to set PWRMGT=1.
                         */
                        ath_power_setselfgen(sc, HAL_PM_NETWORK_SLEEP);

                        /*
                         * If we're not syncing beacons, transition
                         * to NETWORK_SLEEP.
                         *
                         * We stay awake if syncbeacon > 0 in case
                         * we need to listen for some beacons otherwise
                         * our beacon timer config may be wrong.
                         */
                        if (sc->sc_syncbeacon == 0) {
                                ath_power_setpower(sc, HAL_PM_NETWORK_SLEEP);
                        }
                }
        }
bad:
        ieee80211_free_node(ni);

        /*
         * Restore the power state - either to what it was, or
         * to network_sleep if it's alright.
         */
        ath_power_restore_power_state(sc);

        return error;
}

/*
 * Allocate a key cache slot to the station so we can
 * setup a mapping from key index to node. The key cache
 * slot is needed for managing antenna state and for
 * compression when stations do not use crypto.  We do
 * it uniliaterally here; if crypto is employed this slot
 * will be reassigned.
 */
static void
ath_setup_stationkey(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;
        struct ath_softc *sc = vap->iv_ic->ic_ifp->if_softc;
        ieee80211_keyix keyix, rxkeyix;

        /* XXX should take a locked ref to vap->iv_bss */
        if (!ath_key_alloc(vap, &ni->ni_ucastkey, &keyix, &rxkeyix)) {
                /*
                 * Key cache is full; we'll fall back to doing
                 * the more expensive lookup in software.  Note
                 * this also means no h/w compression.
                 */
                /* XXX msg+statistic */
        } else {
                /* XXX locking? */
                ni->ni_ucastkey.wk_keyix = keyix;
                ni->ni_ucastkey.wk_rxkeyix = rxkeyix;
                /* NB: must mark device key to get called back on delete */
                ni->ni_ucastkey.wk_flags |= IEEE80211_KEY_DEVKEY;
                IEEE80211_ADDR_COPY(ni->ni_ucastkey.wk_macaddr, ni->ni_macaddr);
                /* NB: this will create a pass-thru key entry */
                ath_keyset(sc, vap, &ni->ni_ucastkey, vap->iv_bss);
        }
}

/*
 * Setup driver-specific state for a newly associated node.
 * Note that we're called also on a re-associate, the isnew
 * param tells us if this is the first time or not.
 */
static void
ath_newassoc(struct ieee80211_node *ni, int isnew)
{
        struct ath_node *an = ATH_NODE(ni);
        struct ieee80211vap *vap = ni->ni_vap;
        struct ath_softc *sc = vap->iv_ic->ic_ifp->if_softc;
        const struct ieee80211_txparam *tp = ni->ni_txparms;

        an->an_mcastrix = ath_tx_findrix(sc, tp->mcastrate);
        an->an_mgmtrix = ath_tx_findrix(sc, tp->mgmtrate);

        DPRINTF(sc, ATH_DEBUG_NODE,
                "%s: %s: reassoc; isnew=%d, is_powersave=%d\n",
                __func__,
                ath_hal_ether_sprintf(ni->ni_macaddr),
                isnew,
                an->an_is_powersave);

        ATH_NODE_LOCK(an);
        ath_rate_newassoc(sc, an, isnew);
        ATH_NODE_UNLOCK(an);

        if (isnew &&
            (vap->iv_flags & IEEE80211_F_PRIVACY) == 0 && sc->sc_hasclrkey &&
            ni->ni_ucastkey.wk_keyix == IEEE80211_KEYIX_NONE)
                ath_setup_stationkey(ni);

        /*
         * If we're reassociating, make sure that any paused queues
         * get unpaused.
         *
         * Now, we may hvae frames in the hardware queue for this node.
         * So if we are reassociating and there are frames in the queue,
         * we need to go through the cleanup path to ensure that they're
         * marked as non-aggregate.
         */
        if (! isnew) {
                DPRINTF(sc, ATH_DEBUG_NODE,
                    "%s: %s: reassoc; is_powersave=%d\n",
                    __func__,
                    ath_hal_ether_sprintf(ni->ni_macaddr),
                    an->an_is_powersave);

                /* XXX for now, we can't hold the lock across assoc */
                ath_tx_node_reassoc(sc, an);

                /* XXX for now, we can't hold the lock across wakeup */
                if (an->an_is_powersave)
                        ath_tx_node_wakeup(sc, an);
        }
}

static int
ath_setregdomain(struct ieee80211com *ic, struct ieee80211_regdomain *reg,
        int nchans, struct ieee80211_channel chans[])
{
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;
        HAL_STATUS status;

        DPRINTF(sc, ATH_DEBUG_REGDOMAIN,
            "%s: rd %u cc %u location %c%s\n",
            __func__, reg->regdomain, reg->country, reg->location,
            reg->ecm ? " ecm" : "");

        status = ath_hal_set_channels(ah, chans, nchans,
            reg->country, reg->regdomain);
        if (status != HAL_OK) {
                DPRINTF(sc, ATH_DEBUG_REGDOMAIN, "%s: failed, status %u\n",
                    __func__, status);
                return EINVAL;          /* XXX */
        }

        return 0;
}

static void
ath_getradiocaps(struct ieee80211com *ic,
        int maxchans, int *nchans, struct ieee80211_channel chans[])
{
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_hal *ah = sc->sc_ah;

        DPRINTF(sc, ATH_DEBUG_REGDOMAIN, "%s: use rd %u cc %d\n",
            __func__, SKU_DEBUG, CTRY_DEFAULT);

        /* XXX check return */
        (void) ath_hal_getchannels(ah, chans, maxchans, nchans,
            HAL_MODE_ALL, CTRY_DEFAULT, SKU_DEBUG, AH_TRUE);

}

static int
ath_getchannels(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ath_hal *ah = sc->sc_ah;
        HAL_STATUS status;

        /*
         * Collect channel set based on EEPROM contents.
         */
        status = ath_hal_init_channels(ah, ic->ic_channels, IEEE80211_CHAN_MAX,
            &ic->ic_nchans, HAL_MODE_ALL, CTRY_DEFAULT, SKU_NONE, AH_TRUE);
        if (status != HAL_OK) {
                if_printf(ifp, "%s: unable to collect channel list from hal, "
                    "status %d\n", __func__, status);
                return EINVAL;
        }
        (void) ath_hal_getregdomain(ah, &sc->sc_eerd);
        ath_hal_getcountrycode(ah, &sc->sc_eecc);       /* NB: cannot fail */
        /* XXX map Atheros sku's to net80211 SKU's */
        /* XXX net80211 types too small */
        ic->ic_regdomain.regdomain = (uint16_t) sc->sc_eerd;
        ic->ic_regdomain.country = (uint16_t) sc->sc_eecc;
        ic->ic_regdomain.isocc[0] = ' ';        /* XXX don't know */
        ic->ic_regdomain.isocc[1] = ' ';

        ic->ic_regdomain.ecm = 1;
        ic->ic_regdomain.location = 'I';

        DPRINTF(sc, ATH_DEBUG_REGDOMAIN,
            "%s: eeprom rd %u cc %u (mapped rd %u cc %u) location %c%s\n",
            __func__, sc->sc_eerd, sc->sc_eecc,
            ic->ic_regdomain.regdomain, ic->ic_regdomain.country,
            ic->ic_regdomain.location, ic->ic_regdomain.ecm ? " ecm" : "");
        return 0;
}

static int
ath_rate_setup(struct ath_softc *sc, u_int mode)
{
        struct ath_hal *ah = sc->sc_ah;
        const HAL_RATE_TABLE *rt;

        switch (mode) {
        case IEEE80211_MODE_11A:
                rt = ath_hal_getratetable(ah, HAL_MODE_11A);
                break;
        case IEEE80211_MODE_HALF:
                rt = ath_hal_getratetable(ah, HAL_MODE_11A_HALF_RATE);
                break;
        case IEEE80211_MODE_QUARTER:
                rt = ath_hal_getratetable(ah, HAL_MODE_11A_QUARTER_RATE);
                break;
        case IEEE80211_MODE_11B:
                rt = ath_hal_getratetable(ah, HAL_MODE_11B);
                break;
        case IEEE80211_MODE_11G:
                rt = ath_hal_getratetable(ah, HAL_MODE_11G);
                break;
        case IEEE80211_MODE_TURBO_A:
                rt = ath_hal_getratetable(ah, HAL_MODE_108A);
                break;
        case IEEE80211_MODE_TURBO_G:
                rt = ath_hal_getratetable(ah, HAL_MODE_108G);
                break;
        case IEEE80211_MODE_STURBO_A:
                rt = ath_hal_getratetable(ah, HAL_MODE_TURBO);
                break;
        case IEEE80211_MODE_11NA:
                rt = ath_hal_getratetable(ah, HAL_MODE_11NA_HT20);
                break;
        case IEEE80211_MODE_11NG:
                rt = ath_hal_getratetable(ah, HAL_MODE_11NG_HT20);
                break;
        default:
                DPRINTF(sc, ATH_DEBUG_ANY, "%s: invalid mode %u\n",
                        __func__, mode);
                return 0;
        }
        sc->sc_rates[mode] = rt;
        return (rt != NULL);
}

static void
ath_setcurmode(struct ath_softc *sc, enum ieee80211_phymode mode)
{
#define N(a)    (sizeof(a)/sizeof(a[0]))
        /* NB: on/off times from the Atheros NDIS driver, w/ permission */
        static const struct {
                u_int           rate;           /* tx/rx 802.11 rate */
                u_int16_t       timeOn;         /* LED on time (ms) */
                u_int16_t       timeOff;        /* LED off time (ms) */
        } blinkrates[] = {
                { 108,  40,  10 },
                {  96,  44,  11 },
                {  72,  50,  13 },
                {  48,  57,  14 },
                {  36,  67,  16 },
                {  24,  80,  20 },
                {  22, 100,  25 },
                {  18, 133,  34 },
                {  12, 160,  40 },
                {  10, 200,  50 },
                {   6, 240,  58 },
                {   4, 267,  66 },
                {   2, 400, 100 },
                {   0, 500, 130 },
                /* XXX half/quarter rates */
        };
        const HAL_RATE_TABLE *rt;
        int i, j;

        memset(sc->sc_rixmap, 0xff, sizeof(sc->sc_rixmap));
        rt = sc->sc_rates[mode];
        KASSERT(rt != NULL, ("no h/w rate set for phy mode %u", mode));
        for (i = 0; i < rt->rateCount; i++) {
                uint8_t ieeerate = rt->info[i].dot11Rate & IEEE80211_RATE_VAL;
                if (rt->info[i].phy != IEEE80211_T_HT)
                        sc->sc_rixmap[ieeerate] = i;
                else
                        sc->sc_rixmap[ieeerate | IEEE80211_RATE_MCS] = i;
        }
        memset(sc->sc_hwmap, 0, sizeof(sc->sc_hwmap));
        for (i = 0; i < N(sc->sc_hwmap); i++) {
                if (i >= rt->rateCount) {
                        sc->sc_hwmap[i].ledon = (500 * hz) / 1000;
                        sc->sc_hwmap[i].ledoff = (130 * hz) / 1000;
                        continue;
                }
                sc->sc_hwmap[i].ieeerate =
                        rt->info[i].dot11Rate & IEEE80211_RATE_VAL;
                if (rt->info[i].phy == IEEE80211_T_HT)
                        sc->sc_hwmap[i].ieeerate |= IEEE80211_RATE_MCS;
                sc->sc_hwmap[i].txflags = IEEE80211_RADIOTAP_F_DATAPAD;
                if (rt->info[i].shortPreamble ||
                    rt->info[i].phy == IEEE80211_T_OFDM)
                        sc->sc_hwmap[i].txflags |= IEEE80211_RADIOTAP_F_SHORTPRE;
                sc->sc_hwmap[i].rxflags = sc->sc_hwmap[i].txflags;
                for (j = 0; j < N(blinkrates)-1; j++)
                        if (blinkrates[j].rate == sc->sc_hwmap[i].ieeerate)
                                break;
                /* NB: this uses the last entry if the rate isn't found */
                /* XXX beware of overlow */
                sc->sc_hwmap[i].ledon = (blinkrates[j].timeOn * hz) / 1000;
                sc->sc_hwmap[i].ledoff = (blinkrates[j].timeOff * hz) / 1000;
        }
        sc->sc_currates = rt;
        sc->sc_curmode = mode;
        /*
         * All protection frames are transmited at 2Mb/s for
         * 11g, otherwise at 1Mb/s.
         */
        if (mode == IEEE80211_MODE_11G)
                sc->sc_protrix = ath_tx_findrix(sc, 2*2);
        else
                sc->sc_protrix = ath_tx_findrix(sc, 2*1);
        /* NB: caller is responsible for resetting rate control state */
#undef N
}

static void
ath_watchdog(void *arg)
{
        struct ath_softc *sc = arg;
        int do_reset = 0;

        wlan_serialize_enter();
        if (sc->sc_wd_timer != 0 && --sc->sc_wd_timer == 0) {
                struct ifnet *ifp = sc->sc_ifp;
                uint32_t hangs;

                ath_power_set_power_state(sc, HAL_PM_AWAKE);

                if (ath_hal_gethangstate(sc->sc_ah, 0xffff, &hangs) &&
                    hangs != 0) {
                        if_printf(ifp, "%s hang detected (0x%x)\n",
                            hangs & 0xff ? "bb" : "mac", hangs);
                } else
                        if_printf(ifp, "device timeout\n");
                do_reset = 1;
                ifp->if_oerrors++;
                sc->sc_stats.ast_watchdog++;
                ath_power_restore_power_state(sc);
        }

        /*
         * We can't hold the lock across the ath_reset() call.
         *
         * And since this routine can't hold a lock and sleep,
         * do the reset deferred.
         */
        if (do_reset) {
                taskqueue_enqueue(sc->sc_tq, &sc->sc_resettask);
        }

        callout_reset(&sc->sc_wd_ch, hz, ath_watchdog, sc);
        wlan_serialize_exit();
}

/*
 * (DragonFly network start)
 */
static void
ath_start(struct ifnet *ifp, struct ifaltq_subque *ifsq)
{
        struct ath_softc *sc = ifp->if_softc;
        struct mbuf *m;

        wlan_assert_serialized();
        ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);

        if ((ifp->if_flags & IFF_RUNNING) == 0 || sc->sc_invalid) {
                ifq_purge(&ifp->if_snd);
                return;
        }
        ifq_set_oactive(&ifp->if_snd);
        for (;;) {
                m = ifq_dequeue(&ifp->if_snd);
                if (m == NULL)
                        break;
                ath_transmit(ifp, m);
        }
        ifq_clr_oactive(&ifp->if_snd);
}

/*
 * Fetch the rate control statistics for the given node.
 */
static int
ath_ioctl_ratestats(struct ath_softc *sc, struct ath_rateioctl *rs)
{
        struct ath_node *an;
        struct ieee80211com *ic = sc->sc_ifp->if_l2com;
        struct ieee80211_node *ni;
        int error = 0;

        /* Perform a lookup on the given node */
        ni = ieee80211_find_node(&ic->ic_sta, rs->is_u.macaddr);
        if (ni == NULL) {
                error = EINVAL;
                goto bad;
        }

        /* Lock the ath_node */
        an = ATH_NODE(ni);
        ATH_NODE_LOCK(an);

        /* Fetch the rate control stats for this node */
        error = ath_rate_fetch_node_stats(sc, an, rs);

        /* No matter what happens here, just drop through */

        /* Unlock the ath_node */
        ATH_NODE_UNLOCK(an);

        /* Unref the node */
        ieee80211_node_decref(ni);

bad:
        return (error);
}

#ifdef ATH_DIAGAPI
/*
 * Diagnostic interface to the HAL.  This is used by various
 * tools to do things like retrieve register contents for
 * debugging.  The mechanism is intentionally opaque so that
 * it can change frequently w/o concern for compatiblity.
 */
static int
ath_ioctl_diag(struct ath_softc *sc, struct ath_diag *ad)
{
        struct ath_hal *ah = sc->sc_ah;
        u_int id = ad->ad_id & ATH_DIAG_ID;
        void *indata = NULL;
        void *outdata = NULL;
        u_int32_t insize = ad->ad_in_size;
        u_int32_t outsize = ad->ad_out_size;
        int error = 0;

        if (ad->ad_id & ATH_DIAG_IN) {
                /*
                 * Copy in data.
                 */
                indata = kmalloc(insize, M_TEMP, M_INTWAIT);
                if (indata == NULL) {
                        error = ENOMEM;
                        goto bad;
                }
                error = copyin(ad->ad_in_data, indata, insize);
                if (error)
                        goto bad;
        }
        if (ad->ad_id & ATH_DIAG_DYN) {
                /*
                 * Allocate a buffer for the results (otherwise the HAL
                 * returns a pointer to a buffer where we can read the
                 * results).  Note that we depend on the HAL leaving this
                 * pointer for us to use below in reclaiming the buffer;
                 * may want to be more defensive.
                 */
                outdata = kmalloc(outsize, M_TEMP, M_INTWAIT);
                if (outdata == NULL) {
                        error = ENOMEM;
                        goto bad;
                }
        }

        if (id != HAL_DIAG_REGS)
                ath_power_set_power_state(sc, HAL_PM_AWAKE);

        if (ath_hal_getdiagstate(ah, id, indata, insize, &outdata, &outsize)) {
                if (outsize < ad->ad_out_size)
                        ad->ad_out_size = outsize;
                if (outdata != NULL)
                        error = copyout(outdata, ad->ad_out_data,
                                        ad->ad_out_size);
        } else {
                error = EINVAL;
        }
        if (id != HAL_DIAG_REGS)
                ath_power_restore_power_state(sc);
bad:
        if ((ad->ad_id & ATH_DIAG_IN) && indata != NULL)
                kfree(indata, M_TEMP);
        if ((ad->ad_id & ATH_DIAG_DYN) && outdata != NULL)
                kfree(outdata, M_TEMP);
        return error;
}
#endif /* ATH_DIAGAPI */

static int
ath_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data,
          struct ucred *cr __unused)
{
#define IS_RUNNING(ifp) \
        ((ifp->if_flags & IFF_UP) && (ifp->if_flags & IFF_RUNNING))
        struct ath_softc *sc = ifp->if_softc;
        struct ieee80211com *ic = ifp->if_l2com;
        struct ifreq *ifr = (struct ifreq *)data;
        const HAL_RATE_TABLE *rt;
        int error = 0;

        switch (cmd) {
        case SIOCSIFFLAGS:
                ATH_LOCK(sc);
                if (IS_RUNNING(ifp)) {
                        /*
                         * To avoid rescanning another access point,
                         * do not call ath_init() here.  Instead,
                         * only reflect promisc mode settings.
                         */
                        ath_mode_init(sc);
                } else if (ifp->if_flags & IFF_UP) {
                        /*
                         * Beware of being called during attach/detach
                         * to reset promiscuous mode.  In that case we
                         * will still be marked UP but not RUNNING.
                         * However trying to re-init the interface
                         * is the wrong thing to do as we've already
                         * torn down much of our state.  There's
                         * probably a better way to deal with this.
                         */
                        if (!sc->sc_invalid)
                                ath_init(sc);   /* XXX lose error */
                } else {
                        ath_stop_locked(ifp);
                        if (!sc->sc_invalid)
                                ath_power_setpower(sc, HAL_PM_FULL_SLEEP);
                }
                ATH_UNLOCK(sc);
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                error = ifmedia_ioctl(ifp, ifr, &ic->ic_media, cmd);
                break;
        case SIOCGATHSTATS:
                /* NB: embed these numbers to get a consistent view */
                sc->sc_stats.ast_tx_packets = ifp->if_opackets;
                sc->sc_stats.ast_rx_packets = ifp->if_ipackets;
                sc->sc_stats.ast_tx_rssi = ATH_RSSI(sc->sc_halstats.ns_avgtxrssi);
                sc->sc_stats.ast_rx_rssi = ATH_RSSI(sc->sc_halstats.ns_avgrssi);
#ifdef IEEE80211_SUPPORT_TDMA
                sc->sc_stats.ast_tdma_tsfadjp = TDMA_AVG(sc->sc_avgtsfdeltap);
                sc->sc_stats.ast_tdma_tsfadjm = TDMA_AVG(sc->sc_avgtsfdeltam);
#endif
                rt = sc->sc_currates;
                sc->sc_stats.ast_tx_rate =
                    rt->info[sc->sc_txrix].dot11Rate &~ IEEE80211_RATE_BASIC;
                if (rt->info[sc->sc_txrix].phy & IEEE80211_T_HT)
                        sc->sc_stats.ast_tx_rate |= IEEE80211_RATE_MCS;
                return copyout(&sc->sc_stats,
                    ifr->ifr_data, sizeof (sc->sc_stats));
        case SIOCGATHAGSTATS:
                return copyout(&sc->sc_aggr_stats,
                    ifr->ifr_data, sizeof (sc->sc_aggr_stats));
        case SIOCZATHSTATS:
                error = priv_check(curthread, PRIV_DRIVER);
                if (error == 0) {
                        memset(&sc->sc_stats, 0, sizeof(sc->sc_stats));
                        memset(&sc->sc_aggr_stats, 0,
                            sizeof(sc->sc_aggr_stats));
                        memset(&sc->sc_intr_stats, 0,
                            sizeof(sc->sc_intr_stats));
                }
                break;
#ifdef ATH_DIAGAPI
        case SIOCGATHDIAG:
                error = ath_ioctl_diag(sc, (struct ath_diag *) ifr);
                break;
        case SIOCGATHPHYERR:
                error = ath_ioctl_phyerr(sc,(struct ath_diag*) ifr);
                break;
#endif
        case SIOCGATHSPECTRAL:
                error = ath_ioctl_spectral(sc,(struct ath_diag*) ifr);
                break;
        case SIOCGATHNODERATESTATS:
                error = ath_ioctl_ratestats(sc, (struct ath_rateioctl *) ifr);
                break;
        case SIOCGIFADDR:
                error = ether_ioctl(ifp, cmd, data);
                break;
        default:
                error = EINVAL;
                break;
        }
        return error;
#undef IS_RUNNING
}

/*
 * Announce various information on device/driver attach.
 */
static void
ath_announce(struct ath_softc *sc)
{
        struct ifnet *ifp = sc->sc_ifp;
        struct ath_hal *ah = sc->sc_ah;

        if_printf(ifp, "AR%s mac %d.%d RF%s phy %d.%d\n",
                ath_hal_mac_name(ah), ah->ah_macVersion, ah->ah_macRev,
                ath_hal_rf_name(ah), ah->ah_phyRev >> 4, ah->ah_phyRev & 0xf);
        if_printf(ifp, "2GHz radio: 0x%.4x; 5GHz radio: 0x%.4x\n",
                ah->ah_analog2GhzRev, ah->ah_analog5GhzRev);
        if (bootverbose) {
                int i;
                for (i = 0; i <= WME_AC_VO; i++) {
                        struct ath_txq *txq = sc->sc_ac2q[i];
                        if_printf(ifp, "Use hw queue %u for %s traffic\n",
                                txq->axq_qnum, ieee80211_wme_acnames[i]);
                }
                if_printf(ifp, "Use hw queue %u for CAB traffic\n",
                        sc->sc_cabq->axq_qnum);
                if_printf(ifp, "Use hw queue %u for beacons\n", sc->sc_bhalq);
        }
        if (ath_rxbuf != ATH_RXBUF)
                if_printf(ifp, "using %u rx buffers\n", ath_rxbuf);
        if (ath_txbuf != ATH_TXBUF)
                if_printf(ifp, "using %u tx buffers\n", ath_txbuf);
        if (sc->sc_mcastkey && bootverbose)
                if_printf(ifp, "using multicast key search\n");
}

static void
ath_dfs_tasklet(void *p, int npending)
{
        struct ath_softc *sc = (struct ath_softc *) p;
        struct ifnet *ifp = sc->sc_ifp;
        struct ieee80211com *ic = ifp->if_l2com;

        /*
         * If previous processing has found a radar event,
         * signal this to the net80211 layer to begin DFS
         * processing.
         */
        wlan_serialize_enter();
        if (ath_dfs_process_radar_event(sc, sc->sc_curchan)) {
                /* DFS event found, initiate channel change */
                /*
                 * XXX doesn't currently tell us whether the event
                 * XXX was found in the primary or extension
                 * XXX channel!
                 */
                IEEE80211_LOCK(ic);
                ieee80211_dfs_notify_radar(ic, sc->sc_curchan);
                IEEE80211_UNLOCK(ic);
        }
        wlan_serialize_exit();
}

#if 0
/*
 * Enable/disable power save.  This must be called with
 * no TX driver locks currently held, so it should only
 * be called from the RX path (which doesn't hold any
 * TX driver locks.)
 */
static void
ath_node_powersave(struct ieee80211_node *ni, int enable)
{
#ifdef  ATH_SW_PSQ
        struct ath_node *an = ATH_NODE(ni);
        struct ieee80211com *ic = ni->ni_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_vap *avp = ATH_VAP(ni->ni_vap);

        /* XXX and no TXQ locks should be held here */

        DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE, "%s: %6s: enable=%d\n",
            __func__,
            ath_hal_ether_sprintf(ni->ni_macaddr),
            !! enable);

        /* Suspend or resume software queue handling */
        if (enable)
                ath_tx_node_sleep(sc, an);
        else
                ath_tx_node_wakeup(sc, an);

        /* Update net80211 state */
        if (avp->av_node_ps)
                avp->av_node_ps(ni, enable);
#else
        struct ath_vap *avp = ATH_VAP(ni->ni_vap);

        /* Update net80211 state */
        if (avp->av_node_ps)
                avp->av_node_ps(ni, enable);
#endif/* ATH_SW_PSQ */
}

#endif

/*
 * Notification from net80211 that the powersave queue state has
 * changed.
 *
 * Since the software queue also may have some frames:
 *
 * + if the node software queue has frames and the TID state
 *   is 0, we set the TIM;
 * + if the node and the stack are both empty, we clear the TIM bit.
 * + If the stack tries to set the bit, always set it.
 * + If the stack tries to clear the bit, only clear it if the
 *   software queue in question is also cleared.
 *
 * TODO: this is called during node teardown; so let's ensure this
 * is all correctly handled and that the TIM bit is cleared.
 * It may be that the node flush is called _AFTER_ the net80211
 * stack clears the TIM.
 *
 * Here is the racy part.  Since it's possible >1 concurrent,
 * overlapping TXes will appear complete with a TX completion in
 * another thread, it's possible that the concurrent TIM calls will
 * clash.  We can't hold the node lock here because setting the
 * TIM grabs the net80211 comlock and this may cause a LOR.
 * The solution is either to totally serialise _everything_ at
 * this point (ie, all TX, completion and any reset/flush go into
 * one taskqueue) or a new "ath TIM lock" needs to be created that
 * just wraps the driver state change and this call to avp->av_set_tim().
 *
 * The same race exists in the net80211 power save queue handling
 * as well.  Since multiple transmitting threads may queue frames
 * into the driver, as well as ps-poll and the driver transmitting
 * frames (and thus clearing the psq), it's quite possible that
 * a packet entering the PSQ and a ps-poll being handled will
 * race, causing the TIM to be cleared and not re-set.
 */
static int
ath_node_set_tim(struct ieee80211_node *ni, int enable)
{
#ifdef  ATH_SW_PSQ
        struct ieee80211com *ic = ni->ni_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        struct ath_node *an = ATH_NODE(ni);
        struct ath_vap *avp = ATH_VAP(ni->ni_vap);
        int changed = 0;

        ATH_TX_LOCK(sc);
        an->an_stack_psq = enable;

        /*
         * This will get called for all operating modes,
         * even if avp->av_set_tim is unset.
         * It's currently set for hostap/ibss modes; but
         * the same infrastructure is used for both STA
         * and AP/IBSS node power save.
         */
        if (avp->av_set_tim == NULL) {
                ATH_TX_UNLOCK(sc);
                return (0);
        }

        /*
         * If setting the bit, always set it here.
         * If clearing the bit, only clear it if the
         * software queue is also empty.
         *
         * If the node has left power save, just clear the TIM
         * bit regardless of the state of the power save queue.
         *
         * XXX TODO: although atomics are used, it's quite possible
         * that a race will occur between this and setting/clearing
         * in another thread.  TX completion will occur always in
         * one thread, however setting/clearing the TIM bit can come
         * from a variety of different process contexts!
         */
        if (enable && an->an_tim_set == 1) {
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %s: enable=%d, tim_set=1, ignoring\n",
                    __func__,
                    ath_hal_ether_sprintf(ni->ni_macaddr),
                    enable);
                ATH_TX_UNLOCK(sc);
        } else if (enable) {
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %s: enable=%d, enabling TIM\n",
                    __func__,
                    ath_hal_ether_sprintf(ni->ni_macaddr),
                    enable);
                an->an_tim_set = 1;
                ATH_TX_UNLOCK(sc);
                changed = avp->av_set_tim(ni, enable);
        } else if (an->an_swq_depth == 0) {
                /* disable */
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %s: enable=%d, an_swq_depth == 0, disabling\n",
                    __func__,
                    ath_hal_ether_sprintf(ni->ni_macaddr),
                    enable);
                an->an_tim_set = 0;
                ATH_TX_UNLOCK(sc);
                changed = avp->av_set_tim(ni, enable);
        } else if (! an->an_is_powersave) {
                /*
                 * disable regardless; the node isn't in powersave now
                 */
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %s: enable=%d, an_pwrsave=0, disabling\n",
                    __func__,
                    ath_hal_ether_sprintf(ni->ni_macaddr),
                    enable);
                an->an_tim_set = 0;
                ATH_TX_UNLOCK(sc);
                changed = avp->av_set_tim(ni, enable);
        } else {
                /*
                 * psq disable, node is currently in powersave, node
                 * software queue isn't empty, so don't clear the TIM bit
                 * for now.
                 */
                ATH_TX_UNLOCK(sc);
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %s: enable=%d, an_swq_depth > 0, ignoring\n",
                    __func__,
                    ath_hal_ether_sprintf(ni->ni_macaddr),
                    enable);
                changed = 0;
        }

        return (changed);
#else
        struct ath_vap *avp = ATH_VAP(ni->ni_vap);

        /*
         * Some operating modes don't set av_set_tim(), so don't
         * update it here.
         */
        if (avp->av_set_tim == NULL)
                return (0);

        return (avp->av_set_tim(ni, enable));
#endif /* ATH_SW_PSQ */
}

/*
 * Set or update the TIM from the software queue.
 *
 * Check the software queue depth before attempting to do lock
 * anything; that avoids trying to obtain the lock.  Then,
 * re-check afterwards to ensure nothing has changed in the
 * meantime.
 *
 * set:   This is designed to be called from the TX path, after
 *        a frame has been queued; to see if the swq > 0.
 *
 * clear: This is designed to be called from the buffer completion point
 *        (right now it's ath_tx_default_comp()) where the state of
 *        a software queue has changed.
 *
 * It makes sense to place it at buffer free / completion rather
 * than after each software queue operation, as there's no real
 * point in churning the TIM bit as the last frames in the software
 * queue are transmitted.  If they fail and we retry them, we'd
 * just be setting the TIM bit again anyway.
 */
void
ath_tx_update_tim(struct ath_softc *sc, struct ieee80211_node *ni,
     int enable)
{
#ifdef  ATH_SW_PSQ
        struct ath_node *an;
        struct ath_vap *avp;

        /* Don't do this for broadcast/etc frames */
        if (ni == NULL)
                return;

        an = ATH_NODE(ni);
        avp = ATH_VAP(ni->ni_vap);

        /*
         * And for operating modes without the TIM handler set, let's
         * just skip those.
         */
        if (avp->av_set_tim == NULL)
                return;

        ATH_TX_LOCK_ASSERT(sc);

        if (enable) {
                if (an->an_is_powersave &&
                    an->an_tim_set == 0 &&
                    an->an_swq_depth != 0) {
                        DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                            "%s: %s: swq_depth>0, tim_set=0, set!\n",
                            __func__,
                            ath_hal_ether_sprintf(ni->ni_macaddr));
                        an->an_tim_set = 1;
                        (void) avp->av_set_tim(ni, 1);
                }
        } else {
                /*
                 * Don't bother grabbing the lock unless the queue is empty.
                 */
                if (&an->an_swq_depth != 0)
                        return;

                if (an->an_is_powersave &&
                    an->an_stack_psq == 0 &&
                    an->an_tim_set == 1 &&
                    an->an_swq_depth == 0) {
                        DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                            "%s: %s: swq_depth=0, tim_set=1, psq_set=0,"
                            " clear!\n",
                            __func__,
                            ath_hal_ether_sprintf(ni->ni_macaddr));
                        an->an_tim_set = 0;
                        (void) avp->av_set_tim(ni, 0);
                }
        }
#else
        return;
#endif  /* ATH_SW_PSQ */
}

#if 0
/*
 * Received a ps-poll frame from net80211.
 *
 * Here we get a chance to serve out a software-queued frame ourselves
 * before we punt it to net80211 to transmit us one itself - either
 * because there's traffic in the net80211 psq, or a NULL frame to
 * indicate there's nothing else.
 */
static void
ath_node_recv_pspoll(struct ieee80211_node *ni, struct mbuf *m)
{
#ifdef  ATH_SW_PSQ
        struct ath_node *an;
        struct ath_vap *avp;
        struct ieee80211com *ic = ni->ni_ic;
        struct ath_softc *sc = ic->ic_ifp->if_softc;
        int tid;

        /* Just paranoia */
        if (ni == NULL)
                return;

        /*
         * Unassociated (temporary node) station.
         */
        if (ni->ni_associd == 0)
                return;

        /*
         * We do have an active node, so let's begin looking into it.
         */
        an = ATH_NODE(ni);
        avp = ATH_VAP(ni->ni_vap);

        /*
         * For now, we just call the original ps-poll method.
         * Once we're ready to flip this on:
         *
         * + Set leak to 1, as no matter what we're going to have
         *   to send a frame;
         * + Check the software queue and if there's something in it,
         *   schedule the highest TID thas has traffic from this node.
         *   Then make sure we schedule the software scheduler to
         *   run so it picks up said frame.
         *
         * That way whatever happens, we'll at least send _a_ frame
         * to the given node.
         *
         * Again, yes, it's crappy QoS if the node has multiple
         * TIDs worth of traffic - but let's get it working first
         * before we optimise it.
         *
         * Also yes, there's definitely latency here - we're not
         * direct dispatching to the hardware in this path (and
         * we're likely being called from the packet receive path,
         * so going back into TX may be a little hairy!) but again
         * I'd like to get this working first before optimising
         * turn-around time.
         */

        ATH_TX_LOCK(sc);

        /*
         * Legacy - we're called and the node isn't asleep.
         * Immediately punt.
         */
        if (! an->an_is_powersave) {
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %6D: not in powersave?\n",
                    __func__,
                    ni->ni_macaddr,
                    ":");
                ATH_TX_UNLOCK(sc);
                if (avp->av_recv_pspoll)
                        avp->av_recv_pspoll(ni, m);
                return;
        }

        /*
         * We're in powersave.
         *
         * Leak a frame.
         */
        an->an_leak_count = 1;

        /*
         * Now, if there's no frames in the node, just punt to
         * recv_pspoll.
         *
         * Don't bother checking if the TIM bit is set, we really
         * only care if there are any frames here!
         */
        if (an->an_swq_depth == 0) {
                ATH_TX_UNLOCK(sc);
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %6D: SWQ empty; punting to net80211\n",
                    __func__,
                    ni->ni_macaddr,
                    ":");
                if (avp->av_recv_pspoll)
                        avp->av_recv_pspoll(ni, m);
                return;
        }

        /*
         * Ok, let's schedule the highest TID that has traffic
         * and then schedule something.
         */
        for (tid = IEEE80211_TID_SIZE - 1; tid >= 0; tid--) {
                struct ath_tid *atid = &an->an_tid[tid];
                /*
                 * No frames? Skip.
                 */
                if (atid->axq_depth == 0)
                        continue;
                ath_tx_tid_sched(sc, atid);
                /*
                 * XXX we could do a direct call to the TXQ
                 * scheduler code here to optimise latency
                 * at the expense of a REALLY deep callstack.
                 */
                ATH_TX_UNLOCK(sc);
                taskqueue_enqueue(sc->sc_tq, &sc->sc_txqtask);
                DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
                    "%s: %6D: leaking frame to TID %d\n",
                    __func__,
                    ni->ni_macaddr,
                    ":",
                    tid);
                return;
        }

        ATH_TX_UNLOCK(sc);

        /*
         * XXX nothing in the TIDs at this point? Eek.
         */
        DPRINTF(sc, ATH_DEBUG_NODE_PWRSAVE,
            "%s: %6D: TIDs empty, but ath_node showed traffic?!\n",
            __func__,
            ni->ni_macaddr,
            ":");
        if (avp->av_recv_pspoll)
                avp->av_recv_pspoll(ni, m);
#else
        if (avp->av_recv_pspoll)
                avp->av_recv_pspoll(ni, m);
#endif  /* ATH_SW_PSQ */
}

#endif

MODULE_VERSION(if_ath, 1);
MODULE_DEPEND(if_ath, wlan, 1, 1, 1);          /* 802.11 media layer */
#if     defined(IEEE80211_ALQ) || defined(AH_DEBUG_ALQ)
MODULE_DEPEND(if_ath, alq, 1, 1, 1);
#endif