if_printf / device_printf.

[dragonfly.git] / sys / dev / netif / dc / if_dc.c

/*
 * Copyright (c) 1997, 1998, 1999
 *      Bill Paul <wpaul@ee.columbia.edu>.  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.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
 *
 * $FreeBSD: src/sys/pci/if_dc.c,v 1.9.2.45 2003/06/08 14:31:53 mux Exp $
 * $DragonFly: src/sys/dev/netif/dc/if_dc.c,v 1.29 2005/05/31 07:46:17 joerg Exp $
 */

/*
 * DEC "tulip" clone ethernet driver. Supports the DEC/Intel 21143
 * series chips and several workalikes including the following:
 *
 * Macronix 98713/98715/98725/98727/98732 PMAC (www.macronix.com)
 * Macronix/Lite-On 82c115 PNIC II (www.macronix.com)
 * Lite-On 82c168/82c169 PNIC (www.litecom.com)
 * ASIX Electronics AX88140A (www.asix.com.tw)
 * ASIX Electronics AX88141 (www.asix.com.tw)
 * ADMtek AL981 (www.admtek.com.tw)
 * ADMtek AN985 (www.admtek.com.tw)
 * Davicom DM9100, DM9102, DM9102A (www.davicom8.com)
 * Accton EN1217 (www.accton.com)
 * Conexant LANfinity (www.conexant.com)
 *
 * Datasheets for the 21143 are available at developer.intel.com.
 * Datasheets for the clone parts can be found at their respective sites.
 * (Except for the PNIC; see www.freebsd.org/~wpaul/PNIC/pnic.ps.gz.)
 * The PNIC II is essentially a Macronix 98715A chip; the only difference
 * worth noting is that its multicast hash table is only 128 bits wide
 * instead of 512.
 *
 * Written by Bill Paul <wpaul@ee.columbia.edu>
 * Electrical Engineering Department
 * Columbia University, New York City
 */

/*
 * The Intel 21143 is the successor to the DEC 21140. It is basically
 * the same as the 21140 but with a few new features. The 21143 supports
 * three kinds of media attachments:
 *
 * o MII port, for 10Mbps and 100Mbps support and NWAY
 *   autonegotiation provided by an external PHY.
 * o SYM port, for symbol mode 100Mbps support.
 * o 10baseT port.
 * o AUI/BNC port.
 *
 * The 100Mbps SYM port and 10baseT port can be used together in
 * combination with the internal NWAY support to create a 10/100
 * autosensing configuration.
 *
 * Note that not all tulip workalikes are handled in this driver: we only
 * deal with those which are relatively well behaved. The Winbond is
 * handled separately due to its different register offsets and the
 * special handling needed for its various bugs. The PNIC is handled
 * here, but I'm not thrilled about it.
 *
 * All of the workalike chips use some form of MII transceiver support
 * with the exception of the Macronix chips, which also have a SYM port.
 * The ASIX AX88140A is also documented to have a SYM port, but all
 * the cards I've seen use an MII transceiver, probably because the
 * AX88140A doesn't support internal NWAY.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/ifq_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/vlan/if_vlan_var.h>

#include <net/bpf.h>

#include <vm/vm.h>              /* for vtophys */
#include <vm/pmap.h>            /* for vtophys */
#include <machine/clock.h>      /* for DELAY */
#include <machine/bus_pio.h>
#include <machine/bus_memio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include "../mii_layer/mii.h"
#include "../mii_layer/miivar.h"

#include <bus/pci/pcireg.h>
#include <bus/pci/pcivar.h>

#define DC_USEIOSPACE

#include "if_dcreg.h"

/* "controller miibus0" required.  See GENERIC if you get errors here. */
#include "miibus_if.h"

/*
 * Various supported device vendors/types and their names.
 */
static struct dc_type dc_devs[] = {
        { DC_VENDORID_DEC, DC_DEVICEID_21143,
                "Intel 21143 10/100BaseTX" },
        { DC_VENDORID_DAVICOM, DC_DEVICEID_DM9009,
                "Davicom DM9009 10/100BaseTX" },
        { DC_VENDORID_DAVICOM, DC_DEVICEID_DM9100,
                "Davicom DM9100 10/100BaseTX" },
        { DC_VENDORID_DAVICOM, DC_DEVICEID_DM9102,
                "Davicom DM9102 10/100BaseTX" },
        { DC_VENDORID_DAVICOM, DC_DEVICEID_DM9102,
                "Davicom DM9102A 10/100BaseTX" },
        { DC_VENDORID_ADMTEK, DC_DEVICEID_AL981,
                "ADMtek AL981 10/100BaseTX" },
        { DC_VENDORID_ADMTEK, DC_DEVICEID_AN985,
                "ADMtek AN985 10/100BaseTX" },
        { DC_VENDORID_ASIX, DC_DEVICEID_AX88140A,
                "ASIX AX88140A 10/100BaseTX" },
        { DC_VENDORID_ASIX, DC_DEVICEID_AX88140A,
                "ASIX AX88141 10/100BaseTX" },
        { DC_VENDORID_MX, DC_DEVICEID_98713,
                "Macronix 98713 10/100BaseTX" },
        { DC_VENDORID_MX, DC_DEVICEID_98713,
                "Macronix 98713A 10/100BaseTX" },
        { DC_VENDORID_CP, DC_DEVICEID_98713_CP,
                "Compex RL100-TX 10/100BaseTX" },
        { DC_VENDORID_CP, DC_DEVICEID_98713_CP,
                "Compex RL100-TX 10/100BaseTX" },
        { DC_VENDORID_MX, DC_DEVICEID_987x5,
                "Macronix 98715/98715A 10/100BaseTX" },
        { DC_VENDORID_MX, DC_DEVICEID_987x5,
                "Macronix 98715AEC-C 10/100BaseTX" },
        { DC_VENDORID_MX, DC_DEVICEID_987x5,
                "Macronix 98725 10/100BaseTX" },
        { DC_VENDORID_MX, DC_DEVICEID_98727,
                "Macronix 98727/98732 10/100BaseTX" },
        { DC_VENDORID_LO, DC_DEVICEID_82C115,
                "LC82C115 PNIC II 10/100BaseTX" },
        { DC_VENDORID_LO, DC_DEVICEID_82C168,
                "82c168 PNIC 10/100BaseTX" },
        { DC_VENDORID_LO, DC_DEVICEID_82C168,
                "82c169 PNIC 10/100BaseTX" },
        { DC_VENDORID_ACCTON, DC_DEVICEID_EN1217,
                "Accton EN1217 10/100BaseTX" },
        { DC_VENDORID_ACCTON, DC_DEVICEID_EN2242,
                "Accton EN2242 MiniPCI 10/100BaseTX" },
        { DC_VENDORID_CONEXANT, DC_DEVICEID_RS7112,
                "Conexant LANfinity MiniPCI 10/100BaseTX" },
        { DC_VENDORID_3COM, DC_DEVICEID_3CSOHOB,
                "3Com OfficeConnect 10/100B" },
        { 0, 0, NULL }
};

static int dc_probe             (device_t);
static int dc_attach            (device_t);
static int dc_detach            (device_t);
static int dc_suspend           (device_t);
static int dc_resume            (device_t);
static void dc_acpi             (device_t);
static struct dc_type *dc_devtype       (device_t);
static int dc_newbuf            (struct dc_softc *, int, struct mbuf *);
static int dc_encap             (struct dc_softc *, struct mbuf *,
                                        u_int32_t *);
static void dc_pnic_rx_bug_war  (struct dc_softc *, int);
static int dc_rx_resync         (struct dc_softc *);
static void dc_rxeof            (struct dc_softc *);
static void dc_txeof            (struct dc_softc *);
static void dc_tick             (void *);
static void dc_tx_underrun      (struct dc_softc *);
static void dc_intr             (void *);
static void dc_start            (struct ifnet *);
static int dc_ioctl             (struct ifnet *, u_long, caddr_t,
                                        struct ucred *);
#ifdef DEVICE_POLLING
static void dc_poll             (struct ifnet *ifp, enum poll_cmd cmd, 
                                        int count);
#endif
static void dc_init             (void *);
static void dc_stop             (struct dc_softc *);
static void dc_watchdog         (struct ifnet *);
static void dc_shutdown         (device_t);
static int dc_ifmedia_upd       (struct ifnet *);
static void dc_ifmedia_sts      (struct ifnet *, struct ifmediareq *);

static void dc_delay            (struct dc_softc *);
static void dc_eeprom_idle      (struct dc_softc *);
static void dc_eeprom_putbyte   (struct dc_softc *, int);
static void dc_eeprom_getword   (struct dc_softc *, int, u_int16_t *);
static void dc_eeprom_getword_pnic
                                (struct dc_softc *, int, u_int16_t *);
static void dc_eeprom_width     (struct dc_softc *);
static void dc_read_eeprom      (struct dc_softc *, caddr_t, int,
                                                        int, int);

static void dc_mii_writebit     (struct dc_softc *, int);
static int dc_mii_readbit       (struct dc_softc *);
static void dc_mii_sync         (struct dc_softc *);
static void dc_mii_send         (struct dc_softc *, u_int32_t, int);
static int dc_mii_readreg       (struct dc_softc *, struct dc_mii_frame *);
static int dc_mii_writereg      (struct dc_softc *, struct dc_mii_frame *);
static int dc_miibus_readreg    (device_t, int, int);
static int dc_miibus_writereg   (device_t, int, int, int);
static void dc_miibus_statchg   (device_t);
static void dc_miibus_mediainit (device_t);

static void dc_setcfg           (struct dc_softc *, int);
static u_int32_t dc_crc_le      (struct dc_softc *, c_caddr_t);
static u_int32_t dc_crc_be      (caddr_t);
static void dc_setfilt_21143    (struct dc_softc *);
static void dc_setfilt_asix     (struct dc_softc *);
static void dc_setfilt_admtek   (struct dc_softc *);

static void dc_setfilt          (struct dc_softc *);

static void dc_reset            (struct dc_softc *);
static int dc_list_rx_init      (struct dc_softc *);
static int dc_list_tx_init      (struct dc_softc *);

static void dc_read_srom        (struct dc_softc *, int);
static void dc_parse_21143_srom (struct dc_softc *);
static void dc_decode_leaf_sia  (struct dc_softc *,
                                    struct dc_eblock_sia *);
static void dc_decode_leaf_mii  (struct dc_softc *,
                                    struct dc_eblock_mii *);
static void dc_decode_leaf_sym  (struct dc_softc *,
                                    struct dc_eblock_sym *);
static void dc_apply_fixup      (struct dc_softc *, int);

#ifdef DC_USEIOSPACE
#define DC_RES                  SYS_RES_IOPORT
#define DC_RID                  DC_PCI_CFBIO
#else
#define DC_RES                  SYS_RES_MEMORY
#define DC_RID                  DC_PCI_CFBMA
#endif

static device_method_t dc_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         dc_probe),
        DEVMETHOD(device_attach,        dc_attach),
        DEVMETHOD(device_detach,        dc_detach),
        DEVMETHOD(device_suspend,       dc_suspend),
        DEVMETHOD(device_resume,        dc_resume),
        DEVMETHOD(device_shutdown,      dc_shutdown),

        /* bus interface */
        DEVMETHOD(bus_print_child,      bus_generic_print_child),
        DEVMETHOD(bus_driver_added,     bus_generic_driver_added),

        /* MII interface */
        DEVMETHOD(miibus_readreg,       dc_miibus_readreg),
        DEVMETHOD(miibus_writereg,      dc_miibus_writereg),
        DEVMETHOD(miibus_statchg,       dc_miibus_statchg),
        DEVMETHOD(miibus_mediainit,     dc_miibus_mediainit),

        { 0, 0 }
};

static driver_t dc_driver = {
        "dc",
        dc_methods,
        sizeof(struct dc_softc)
};

static devclass_t dc_devclass;

#ifdef __i386__
static int dc_quick=1;
SYSCTL_INT(_hw, OID_AUTO, dc_quick, CTLFLAG_RW,
        &dc_quick,0,"do not mdevget in dc driver");
#endif

DECLARE_DUMMY_MODULE(if_dc);
DRIVER_MODULE(if_dc, pci, dc_driver, dc_devclass, 0, 0);
DRIVER_MODULE(miibus, dc, miibus_driver, miibus_devclass, 0, 0);

#define DC_SETBIT(sc, reg, x)                           \
        CSR_WRITE_4(sc, reg, CSR_READ_4(sc, reg) | (x))

#define DC_CLRBIT(sc, reg, x)                           \
        CSR_WRITE_4(sc, reg, CSR_READ_4(sc, reg) & ~(x))

#define SIO_SET(x)      DC_SETBIT(sc, DC_SIO, (x))
#define SIO_CLR(x)      DC_CLRBIT(sc, DC_SIO, (x))

static void dc_delay(sc)
        struct dc_softc         *sc;
{
        int                     idx;

        for (idx = (300 / 33) + 1; idx > 0; idx--)
                CSR_READ_4(sc, DC_BUSCTL);
}

static void dc_eeprom_width(sc)
        struct dc_softc         *sc;
{
        int i;

        /* Force EEPROM to idle state. */
        dc_eeprom_idle(sc);

        /* Enter EEPROM access mode. */
        CSR_WRITE_4(sc, DC_SIO, DC_SIO_EESEL);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_ROMCTL_READ);
        dc_delay(sc);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CS);
        dc_delay(sc);

        for (i = 3; i--;) {
                if (6 & (1 << i))
                        DC_SETBIT(sc, DC_SIO, DC_SIO_EE_DATAIN);
                else
                        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_DATAIN);
                dc_delay(sc);
                DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
                DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
        }

        for (i = 1; i <= 12; i++) {
                DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
                if (!(CSR_READ_4(sc, DC_SIO) & DC_SIO_EE_DATAOUT)) {
                        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                        dc_delay(sc);
                        break;
                }
                DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
        }

        /* Turn off EEPROM access mode. */
        dc_eeprom_idle(sc);

        if (i < 4 || i > 12)
                sc->dc_romwidth = 6;
        else
                sc->dc_romwidth = i;

        /* Enter EEPROM access mode. */
        CSR_WRITE_4(sc, DC_SIO, DC_SIO_EESEL);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_ROMCTL_READ);
        dc_delay(sc);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CS);
        dc_delay(sc);

        /* Turn off EEPROM access mode. */
        dc_eeprom_idle(sc);
}

static void dc_eeprom_idle(sc)
        struct dc_softc         *sc;
{
        int             i;

        CSR_WRITE_4(sc, DC_SIO, DC_SIO_EESEL);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_ROMCTL_READ);
        dc_delay(sc);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CS);
        dc_delay(sc);

        for (i = 0; i < 25; i++) {
                DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
                DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
        }

        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
        dc_delay(sc);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CS);
        dc_delay(sc);
        CSR_WRITE_4(sc, DC_SIO, 0x00000000);

        return;
}

/*
 * Send a read command and address to the EEPROM, check for ACK.
 */
static void dc_eeprom_putbyte(sc, addr)
        struct dc_softc         *sc;
        int                     addr;
{
        int             d, i;

        d = DC_EECMD_READ >> 6;
        for (i = 3; i--; ) {
                if (d & (1 << i))
                        DC_SETBIT(sc, DC_SIO, DC_SIO_EE_DATAIN);
                else
                        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_DATAIN);
                dc_delay(sc);
                DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
                DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
                dc_delay(sc);
        }

        /*
         * Feed in each bit and strobe the clock.
         */
        for (i = sc->dc_romwidth; i--;) {
                if (addr & (1 << i)) {
                        SIO_SET(DC_SIO_EE_DATAIN);
                } else {
                        SIO_CLR(DC_SIO_EE_DATAIN);
                }
                dc_delay(sc);
                SIO_SET(DC_SIO_EE_CLK);
                dc_delay(sc);
                SIO_CLR(DC_SIO_EE_CLK);
                dc_delay(sc);
        }

        return;
}

/*
 * Read a word of data stored in the EEPROM at address 'addr.'
 * The PNIC 82c168/82c169 has its own non-standard way to read
 * the EEPROM.
 */
static void dc_eeprom_getword_pnic(sc, addr, dest)
        struct dc_softc         *sc;
        int                     addr;
        u_int16_t               *dest;
{
        int             i;
        u_int32_t               r;

        CSR_WRITE_4(sc, DC_PN_SIOCTL, DC_PN_EEOPCODE_READ|addr);

        for (i = 0; i < DC_TIMEOUT; i++) {
                DELAY(1);
                r = CSR_READ_4(sc, DC_SIO);
                if (!(r & DC_PN_SIOCTL_BUSY)) {
                        *dest = (u_int16_t)(r & 0xFFFF);
                        return;
                }
        }

        return;
}

/*
 * Read a word of data stored in the EEPROM at address 'addr.'
 */
static void dc_eeprom_getword(sc, addr, dest)
        struct dc_softc         *sc;
        int                     addr;
        u_int16_t               *dest;
{
        int             i;
        u_int16_t               word = 0;

        /* Force EEPROM to idle state. */
        dc_eeprom_idle(sc);

        /* Enter EEPROM access mode. */
        CSR_WRITE_4(sc, DC_SIO, DC_SIO_EESEL);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO,  DC_SIO_ROMCTL_READ);
        dc_delay(sc);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_EE_CLK);
        dc_delay(sc);
        DC_SETBIT(sc, DC_SIO, DC_SIO_EE_CS);
        dc_delay(sc);

        /*
         * Send address of word we want to read.
         */
        dc_eeprom_putbyte(sc, addr);

        /*
         * Start reading bits from EEPROM.
         */
        for (i = 0x8000; i; i >>= 1) {
                SIO_SET(DC_SIO_EE_CLK);
                dc_delay(sc);
                if (CSR_READ_4(sc, DC_SIO) & DC_SIO_EE_DATAOUT)
                        word |= i;
                dc_delay(sc);
                SIO_CLR(DC_SIO_EE_CLK);
                dc_delay(sc);
        }

        /* Turn off EEPROM access mode. */
        dc_eeprom_idle(sc);

        *dest = word;

        return;
}

/*
 * Read a sequence of words from the EEPROM.
 */
static void dc_read_eeprom(sc, dest, off, cnt, swap)
        struct dc_softc         *sc;
        caddr_t                 dest;
        int                     off;
        int                     cnt;
        int                     swap;
{
        int                     i;
        u_int16_t               word = 0, *ptr;

        for (i = 0; i < cnt; i++) {
                if (DC_IS_PNIC(sc))
                        dc_eeprom_getword_pnic(sc, off + i, &word);
                else
                        dc_eeprom_getword(sc, off + i, &word);
                ptr = (u_int16_t *)(dest + (i * 2));
                if (swap)
                        *ptr = ntohs(word);
                else
                        *ptr = word;
        }

        return;
}

/*
 * The following two routines are taken from the Macronix 98713
 * Application Notes pp.19-21.
 */
/*
 * Write a bit to the MII bus.
 */
static void dc_mii_writebit(sc, bit)
        struct dc_softc         *sc;
        int                     bit;
{
        if (bit)
                CSR_WRITE_4(sc, DC_SIO,
                    DC_SIO_ROMCTL_WRITE|DC_SIO_MII_DATAOUT);
        else
                CSR_WRITE_4(sc, DC_SIO, DC_SIO_ROMCTL_WRITE);

        DC_SETBIT(sc, DC_SIO, DC_SIO_MII_CLK);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_MII_CLK);

        return;
}

/*
 * Read a bit from the MII bus.
 */
static int dc_mii_readbit(sc)
        struct dc_softc         *sc;
{
        CSR_WRITE_4(sc, DC_SIO, DC_SIO_ROMCTL_READ|DC_SIO_MII_DIR);
        CSR_READ_4(sc, DC_SIO);
        DC_SETBIT(sc, DC_SIO, DC_SIO_MII_CLK);
        DC_CLRBIT(sc, DC_SIO, DC_SIO_MII_CLK);
        if (CSR_READ_4(sc, DC_SIO) & DC_SIO_MII_DATAIN)
                return(1);

        return(0);
}

/*
 * Sync the PHYs by setting data bit and strobing the clock 32 times.
 */
static void dc_mii_sync(sc)
        struct dc_softc         *sc;
{
        int             i;

        CSR_WRITE_4(sc, DC_SIO, DC_SIO_ROMCTL_WRITE);

        for (i = 0; i < 32; i++)
                dc_mii_writebit(sc, 1);

        return;
}

/*
 * Clock a series of bits through the MII.
 */
static void dc_mii_send(sc, bits, cnt)
        struct dc_softc         *sc;
        u_int32_t               bits;
        int                     cnt;
{
        int                     i;

        for (i = (0x1 << (cnt - 1)); i; i >>= 1)
                dc_mii_writebit(sc, bits & i);
}

/*
 * Read an PHY register through the MII.
 */
static int dc_mii_readreg(sc, frame)
        struct dc_softc         *sc;
        struct dc_mii_frame     *frame;
        
{
        int                     i, ack, s;

        s = splimp();

        /*
         * Set up frame for RX.
         */
        frame->mii_stdelim = DC_MII_STARTDELIM;
        frame->mii_opcode = DC_MII_READOP;
        frame->mii_turnaround = 0;
        frame->mii_data = 0;
        
        /*
         * Sync the PHYs.
         */
        dc_mii_sync(sc);

        /*
         * Send command/address info.
         */
        dc_mii_send(sc, frame->mii_stdelim, 2);
        dc_mii_send(sc, frame->mii_opcode, 2);
        dc_mii_send(sc, frame->mii_phyaddr, 5);
        dc_mii_send(sc, frame->mii_regaddr, 5);

#ifdef notdef
        /* Idle bit */
        dc_mii_writebit(sc, 1);
        dc_mii_writebit(sc, 0);
#endif

        /* Check for ack */
        ack = dc_mii_readbit(sc);

        /*
         * Now try reading data bits. If the ack failed, we still
         * need to clock through 16 cycles to keep the PHY(s) in sync.
         */
        if (ack) {
                for(i = 0; i < 16; i++) {
                        dc_mii_readbit(sc);
                }
                goto fail;
        }

        for (i = 0x8000; i; i >>= 1) {
                if (!ack) {
                        if (dc_mii_readbit(sc))
                                frame->mii_data |= i;
                }
        }

fail:

        dc_mii_writebit(sc, 0);
        dc_mii_writebit(sc, 0);

        splx(s);

        if (ack)
                return(1);
        return(0);
}

/*
 * Write to a PHY register through the MII.
 */
static int dc_mii_writereg(sc, frame)
        struct dc_softc         *sc;
        struct dc_mii_frame     *frame;
        
{
        int                     s;

        s = splimp();
        /*
         * Set up frame for TX.
         */

        frame->mii_stdelim = DC_MII_STARTDELIM;
        frame->mii_opcode = DC_MII_WRITEOP;
        frame->mii_turnaround = DC_MII_TURNAROUND;

        /*
         * Sync the PHYs.
         */     
        dc_mii_sync(sc);

        dc_mii_send(sc, frame->mii_stdelim, 2);
        dc_mii_send(sc, frame->mii_opcode, 2);
        dc_mii_send(sc, frame->mii_phyaddr, 5);
        dc_mii_send(sc, frame->mii_regaddr, 5);
        dc_mii_send(sc, frame->mii_turnaround, 2);
        dc_mii_send(sc, frame->mii_data, 16);

        /* Idle bit. */
        dc_mii_writebit(sc, 0);
        dc_mii_writebit(sc, 0);

        splx(s);

        return(0);
}

static int dc_miibus_readreg(dev, phy, reg)
        device_t                dev;
        int                     phy, reg;
{
        struct dc_mii_frame     frame;
        struct dc_softc         *sc;
        int                     i, rval, phy_reg = 0;

        sc = device_get_softc(dev);
        bzero((char *)&frame, sizeof(frame));

        /*
         * Note: both the AL981 and AN985 have internal PHYs,
         * however the AL981 provides direct access to the PHY
         * registers while the AN985 uses a serial MII interface.
         * The AN985's MII interface is also buggy in that you
         * can read from any MII address (0 to 31), but only address 1
         * behaves normally. To deal with both cases, we pretend
         * that the PHY is at MII address 1.
         */
        if (DC_IS_ADMTEK(sc) && phy != DC_ADMTEK_PHYADDR)
                return(0);

        /*
         * Note: the ukphy probes of the RS7112 report a PHY at
         * MII address 0 (possibly HomePNA?) and 1 (ethernet)
         * so we only respond to correct one.
         */
        if (DC_IS_CONEXANT(sc) && phy != DC_CONEXANT_PHYADDR)
                return(0);

        if (sc->dc_pmode != DC_PMODE_MII) {
                if (phy == (MII_NPHY - 1)) {
                        switch(reg) {
                        case MII_BMSR:
                        /*
                         * Fake something to make the probe
                         * code think there's a PHY here.
                         */
                                return(BMSR_MEDIAMASK);
                                break;
                        case MII_PHYIDR1:
                                if (DC_IS_PNIC(sc))
                                        return(DC_VENDORID_LO);
                                return(DC_VENDORID_DEC);
                                break;
                        case MII_PHYIDR2:
                                if (DC_IS_PNIC(sc))
                                        return(DC_DEVICEID_82C168);
                                return(DC_DEVICEID_21143);
                                break;
                        default:
                                return(0);
                                break;
                        }
                } else
                        return(0);
        }

        if (DC_IS_PNIC(sc)) {
                CSR_WRITE_4(sc, DC_PN_MII, DC_PN_MIIOPCODE_READ |
                    (phy << 23) | (reg << 18));
                for (i = 0; i < DC_TIMEOUT; i++) {
                        DELAY(1);
                        rval = CSR_READ_4(sc, DC_PN_MII);
                        if (!(rval & DC_PN_MII_BUSY)) {
                                rval &= 0xFFFF;
                                return(rval == 0xFFFF ? 0 : rval);
                        }
                }
                return(0);
        }

        if (DC_IS_COMET(sc)) {
                switch(reg) {
                case MII_BMCR:
                        phy_reg = DC_AL_BMCR;
                        break;
                case MII_BMSR:
                        phy_reg = DC_AL_BMSR;
                        break;
                case MII_PHYIDR1:
                        phy_reg = DC_AL_VENID;
                        break;
                case MII_PHYIDR2:
                        phy_reg = DC_AL_DEVID;
                        break;
                case MII_ANAR:
                        phy_reg = DC_AL_ANAR;
                        break;
                case MII_ANLPAR:
                        phy_reg = DC_AL_LPAR;
                        break;
                case MII_ANER:
                        phy_reg = DC_AL_ANER;
                        break;
                default:
                        if_printf(&sc->arpcom.ac_if,
                                  "phy_read: bad phy register %x\n", reg);
                        return(0);
                        break;
                }

                rval = CSR_READ_4(sc, phy_reg) & 0x0000FFFF;

                if (rval == 0xFFFF)
                        return(0);
                return(rval);
        }

        frame.mii_phyaddr = phy;
        frame.mii_regaddr = reg;
        if (sc->dc_type == DC_TYPE_98713) {
                phy_reg = CSR_READ_4(sc, DC_NETCFG);
                CSR_WRITE_4(sc, DC_NETCFG, phy_reg & ~DC_NETCFG_PORTSEL);
        }
        dc_mii_readreg(sc, &frame);
        if (sc->dc_type == DC_TYPE_98713)
                CSR_WRITE_4(sc, DC_NETCFG, phy_reg);

        return(frame.mii_data);
}

static int dc_miibus_writereg(dev, phy, reg, data)
        device_t                dev;
        int                     phy, reg, data;
{
        struct dc_softc         *sc;
        struct dc_mii_frame     frame;
        int                     i, phy_reg = 0;

        sc = device_get_softc(dev);
        bzero((char *)&frame, sizeof(frame));

        if (DC_IS_ADMTEK(sc) && phy != DC_ADMTEK_PHYADDR)
                return(0);

        if (DC_IS_CONEXANT(sc) && phy != DC_CONEXANT_PHYADDR)
                return(0);

        if (DC_IS_PNIC(sc)) {
                CSR_WRITE_4(sc, DC_PN_MII, DC_PN_MIIOPCODE_WRITE |
                    (phy << 23) | (reg << 10) | data);
                for (i = 0; i < DC_TIMEOUT; i++) {
                        if (!(CSR_READ_4(sc, DC_PN_MII) & DC_PN_MII_BUSY))
                                break;
                }
                return(0);
        }

        if (DC_IS_COMET(sc)) {
                switch(reg) {
                case MII_BMCR:
                        phy_reg = DC_AL_BMCR;
                        break;
                case MII_BMSR:
                        phy_reg = DC_AL_BMSR;
                        break;
                case MII_PHYIDR1:
                        phy_reg = DC_AL_VENID;
                        break;
                case MII_PHYIDR2:
                        phy_reg = DC_AL_DEVID;
                        break;
                case MII_ANAR:
                        phy_reg = DC_AL_ANAR;
                        break;
                case MII_ANLPAR:
                        phy_reg = DC_AL_LPAR;
                        break;
                case MII_ANER:
                        phy_reg = DC_AL_ANER;
                        break;
                default:
                        if_printf(&sc->arpcom.ac_if,
                                  "phy_write: bad phy register %x\n", reg);
                        return(0);
                        break;
                }

                CSR_WRITE_4(sc, phy_reg, data);
                return(0);
        }

        frame.mii_phyaddr = phy;
        frame.mii_regaddr = reg;
        frame.mii_data = data;

        if (sc->dc_type == DC_TYPE_98713) {
                phy_reg = CSR_READ_4(sc, DC_NETCFG);
                CSR_WRITE_4(sc, DC_NETCFG, phy_reg & ~DC_NETCFG_PORTSEL);
        }
        dc_mii_writereg(sc, &frame);
        if (sc->dc_type == DC_TYPE_98713)
                CSR_WRITE_4(sc, DC_NETCFG, phy_reg);

        return(0);
}

static void dc_miibus_statchg(dev)
        device_t                dev;
{
        struct dc_softc         *sc;
        struct mii_data         *mii;
        struct ifmedia          *ifm;

        sc = device_get_softc(dev);
        if (DC_IS_ADMTEK(sc))
                return;

        mii = device_get_softc(sc->dc_miibus);
        ifm = &mii->mii_media;
        if (DC_IS_DAVICOM(sc) &&
            IFM_SUBTYPE(ifm->ifm_media) == IFM_HPNA_1) {
                dc_setcfg(sc, ifm->ifm_media);
                sc->dc_if_media = ifm->ifm_media;
        } else {
                dc_setcfg(sc, mii->mii_media_active);
                sc->dc_if_media = mii->mii_media_active;
        }

        return;
}

/*
 * Special support for DM9102A cards with HomePNA PHYs. Note:
 * with the Davicom DM9102A/DM9801 eval board that I have, it seems
 * to be impossible to talk to the management interface of the DM9801
 * PHY (its MDIO pin is not connected to anything). Consequently,
 * the driver has to just 'know' about the additional mode and deal
 * with it itself. *sigh*
 */
static void dc_miibus_mediainit(dev)
        device_t                dev;
{
        struct dc_softc         *sc;
        struct mii_data         *mii;
        struct ifmedia          *ifm;
        int                     rev;

        rev = pci_read_config(dev, DC_PCI_CFRV, 4) & 0xFF;

        sc = device_get_softc(dev);
        mii = device_get_softc(sc->dc_miibus);
        ifm = &mii->mii_media;

        if (DC_IS_DAVICOM(sc) && rev >= DC_REVISION_DM9102A)
                ifmedia_add(ifm, IFM_ETHER | IFM_HPNA_1, 0, NULL);

        return;
}

#define DC_POLY         0xEDB88320
#define DC_BITS_512     9
#define DC_BITS_128     7
#define DC_BITS_64      6

static u_int32_t dc_crc_le(sc, addr)
        struct dc_softc         *sc;
        c_caddr_t               addr;
{
        u_int32_t               idx, bit, data, crc;

        /* Compute CRC for the address value. */
        crc = 0xFFFFFFFF; /* initial value */

        for (idx = 0; idx < 6; idx++) {
                for (data = *addr++, bit = 0; bit < 8; bit++, data >>= 1)
                        crc = (crc >> 1) ^ (((crc ^ data) & 1) ? DC_POLY : 0);
        }

        /*
         * The hash table on the PNIC II and the MX98715AEC-C/D/E
         * chips is only 128 bits wide.
         */
        if (sc->dc_flags & DC_128BIT_HASH)
                return (crc & ((1 << DC_BITS_128) - 1));

        /* The hash table on the MX98715BEC is only 64 bits wide. */
        if (sc->dc_flags & DC_64BIT_HASH)
                return (crc & ((1 << DC_BITS_64) - 1));

        return (crc & ((1 << DC_BITS_512) - 1));
}

/*
 * Calculate CRC of a multicast group address, return the lower 6 bits.
 */
static u_int32_t dc_crc_be(addr)
        caddr_t                 addr;
{
        u_int32_t               crc, carry;
        int                     i, j;
        u_int8_t                c;

        /* Compute CRC for the address value. */
        crc = 0xFFFFFFFF; /* initial value */

        for (i = 0; i < 6; i++) {
                c = *(addr + i);
                for (j = 0; j < 8; j++) {
                        carry = ((crc & 0x80000000) ? 1 : 0) ^ (c & 0x01);
                        crc <<= 1;
                        c >>= 1;
                        if (carry)
                                crc = (crc ^ 0x04c11db6) | carry;
                }
        }

        /* return the filter bit position */
        return((crc >> 26) & 0x0000003F);
}

/*
 * 21143-style RX filter setup routine. Filter programming is done by
 * downloading a special setup frame into the TX engine. 21143, Macronix,
 * PNIC, PNIC II and Davicom chips are programmed this way.
 *
 * We always program the chip using 'hash perfect' mode, i.e. one perfect
 * address (our node address) and a 512-bit hash filter for multicast
 * frames. We also sneak the broadcast address into the hash filter since
 * we need that too.
 */
void dc_setfilt_21143(sc)
        struct dc_softc         *sc;
{
        struct dc_desc          *sframe;
        u_int32_t               h, *sp;
        struct ifmultiaddr      *ifma;
        struct ifnet            *ifp;
        int                     i;

        ifp = &sc->arpcom.ac_if;

        i = sc->dc_cdata.dc_tx_prod;
        DC_INC(sc->dc_cdata.dc_tx_prod, DC_TX_LIST_CNT);
        sc->dc_cdata.dc_tx_cnt++;
        sframe = &sc->dc_ldata->dc_tx_list[i];
        sp = (u_int32_t *)&sc->dc_cdata.dc_sbuf;
        bzero((char *)sp, DC_SFRAME_LEN);

        sframe->dc_data = vtophys(&sc->dc_cdata.dc_sbuf);
        sframe->dc_ctl = DC_SFRAME_LEN | DC_TXCTL_SETUP | DC_TXCTL_TLINK |
            DC_FILTER_HASHPERF | DC_TXCTL_FINT;

        sc->dc_cdata.dc_tx_chain[i] = (struct mbuf *)&sc->dc_cdata.dc_sbuf;

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_PROMISC);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_RX_PROMISC);

        if (ifp->if_flags & IFF_ALLMULTI)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_ALLMULTI);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_RX_ALLMULTI);

        for (ifma = ifp->if_multiaddrs.lh_first; ifma != NULL;
            ifma = ifma->ifma_link.le_next) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                h = dc_crc_le(sc,
                    LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
                sp[h >> 4] |= 1 << (h & 0xF);
        }

        if (ifp->if_flags & IFF_BROADCAST) {
                h = dc_crc_le(sc, ifp->if_broadcastaddr);
                sp[h >> 4] |= 1 << (h & 0xF);
        }

        /* Set our MAC address */
        sp[39] = ((u_int16_t *)sc->arpcom.ac_enaddr)[0];
        sp[40] = ((u_int16_t *)sc->arpcom.ac_enaddr)[1];
        sp[41] = ((u_int16_t *)sc->arpcom.ac_enaddr)[2];

        sframe->dc_status = DC_TXSTAT_OWN;
        CSR_WRITE_4(sc, DC_TXSTART, 0xFFFFFFFF);

        /*
         * The PNIC takes an exceedingly long time to process its
         * setup frame; wait 10ms after posting the setup frame
         * before proceeding, just so it has time to swallow its
         * medicine.
         */
        DELAY(10000);

        ifp->if_timer = 5;

        return;
}

void dc_setfilt_admtek(sc)
        struct dc_softc         *sc;
{
        struct ifnet            *ifp;
        int                     h = 0;
        u_int32_t               hashes[2] = { 0, 0 };
        struct ifmultiaddr      *ifma;

        ifp = &sc->arpcom.ac_if;

        /* Init our MAC address */
        CSR_WRITE_4(sc, DC_AL_PAR0, *(u_int32_t *)(&sc->arpcom.ac_enaddr[0]));
        CSR_WRITE_4(sc, DC_AL_PAR1, *(u_int32_t *)(&sc->arpcom.ac_enaddr[4]));

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_PROMISC);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_RX_PROMISC);

        if (ifp->if_flags & IFF_ALLMULTI)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_ALLMULTI);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_RX_ALLMULTI);

        /* first, zot all the existing hash bits */
        CSR_WRITE_4(sc, DC_AL_MAR0, 0);
        CSR_WRITE_4(sc, DC_AL_MAR1, 0);

        /*
         * If we're already in promisc or allmulti mode, we
         * don't have to bother programming the multicast filter.
         */
        if (ifp->if_flags & (IFF_PROMISC|IFF_ALLMULTI))
                return;

        /* now program new ones */
        for (ifma = ifp->if_multiaddrs.lh_first; ifma != NULL;
            ifma = ifma->ifma_link.le_next) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                if (DC_IS_CENTAUR(sc))
                        h = dc_crc_le(sc, LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
                else
                        h = dc_crc_be(LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
                if (h < 32)
                        hashes[0] |= (1 << h);
                else
                        hashes[1] |= (1 << (h - 32));
        }

        CSR_WRITE_4(sc, DC_AL_MAR0, hashes[0]);
        CSR_WRITE_4(sc, DC_AL_MAR1, hashes[1]);

        return;
}

void dc_setfilt_asix(sc)
        struct dc_softc         *sc;
{
        struct ifnet            *ifp;
        int                     h = 0;
        u_int32_t               hashes[2] = { 0, 0 };
        struct ifmultiaddr      *ifma;

        ifp = &sc->arpcom.ac_if;

        /* Init our MAC address */
        CSR_WRITE_4(sc, DC_AX_FILTIDX, DC_AX_FILTIDX_PAR0);
        CSR_WRITE_4(sc, DC_AX_FILTDATA,
            *(u_int32_t *)(&sc->arpcom.ac_enaddr[0]));
        CSR_WRITE_4(sc, DC_AX_FILTIDX, DC_AX_FILTIDX_PAR1);
        CSR_WRITE_4(sc, DC_AX_FILTDATA,
            *(u_int32_t *)(&sc->arpcom.ac_enaddr[4]));

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_PROMISC);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_RX_PROMISC);

        if (ifp->if_flags & IFF_ALLMULTI)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_ALLMULTI);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_RX_ALLMULTI);

        /*
         * The ASIX chip has a special bit to enable reception
         * of broadcast frames.
         */
        if (ifp->if_flags & IFF_BROADCAST)
                DC_SETBIT(sc, DC_NETCFG, DC_AX_NETCFG_RX_BROAD);
        else
                DC_CLRBIT(sc, DC_NETCFG, DC_AX_NETCFG_RX_BROAD);

        /* first, zot all the existing hash bits */
        CSR_WRITE_4(sc, DC_AX_FILTIDX, DC_AX_FILTIDX_MAR0);
        CSR_WRITE_4(sc, DC_AX_FILTDATA, 0);
        CSR_WRITE_4(sc, DC_AX_FILTIDX, DC_AX_FILTIDX_MAR1);
        CSR_WRITE_4(sc, DC_AX_FILTDATA, 0);

        /*
         * If we're already in promisc or allmulti mode, we
         * don't have to bother programming the multicast filter.
         */
        if (ifp->if_flags & (IFF_PROMISC|IFF_ALLMULTI))
                return;

        /* now program new ones */
        for (ifma = ifp->if_multiaddrs.lh_first; ifma != NULL;
            ifma = ifma->ifma_link.le_next) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                h = dc_crc_be(LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
                if (h < 32)
                        hashes[0] |= (1 << h);
                else
                        hashes[1] |= (1 << (h - 32));
        }

        CSR_WRITE_4(sc, DC_AX_FILTIDX, DC_AX_FILTIDX_MAR0);
        CSR_WRITE_4(sc, DC_AX_FILTDATA, hashes[0]);
        CSR_WRITE_4(sc, DC_AX_FILTIDX, DC_AX_FILTIDX_MAR1);
        CSR_WRITE_4(sc, DC_AX_FILTDATA, hashes[1]);

        return;
}

static void dc_setfilt(sc)
        struct dc_softc         *sc;
{
        if (DC_IS_INTEL(sc) || DC_IS_MACRONIX(sc) || DC_IS_PNIC(sc) ||
            DC_IS_PNICII(sc) || DC_IS_DAVICOM(sc) || DC_IS_CONEXANT(sc))
                dc_setfilt_21143(sc);

        if (DC_IS_ASIX(sc))
                dc_setfilt_asix(sc);

        if (DC_IS_ADMTEK(sc))
                dc_setfilt_admtek(sc);

        return;
}

/*
 * In order to fiddle with the
 * 'full-duplex' and '100Mbps' bits in the netconfig register, we
 * first have to put the transmit and/or receive logic in the idle state.
 */
static void dc_setcfg(sc, media)
        struct dc_softc         *sc;
        int                     media;
{
        int                     i, restart = 0;
        u_int32_t               isr;

        if (IFM_SUBTYPE(media) == IFM_NONE)
                return;

        if (CSR_READ_4(sc, DC_NETCFG) & (DC_NETCFG_TX_ON|DC_NETCFG_RX_ON)) {
                restart = 1;
                DC_CLRBIT(sc, DC_NETCFG, (DC_NETCFG_TX_ON|DC_NETCFG_RX_ON));

                for (i = 0; i < DC_TIMEOUT; i++) {
                        isr = CSR_READ_4(sc, DC_ISR);
                        if (isr & DC_ISR_TX_IDLE ||
                            (isr & DC_ISR_RX_STATE) == DC_RXSTATE_STOPPED)
                                break;
                        DELAY(10);
                }

                if (i == DC_TIMEOUT) {
                        if_printf(&sc->arpcom.ac_if, 
                            "failed to force tx and rx to idle state\n");
                }
        }

        if (IFM_SUBTYPE(media) == IFM_100_TX) {
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_SPEEDSEL);
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_HEARTBEAT);
                if (sc->dc_pmode == DC_PMODE_MII) {
                        int     watchdogreg;

                        if (DC_IS_INTEL(sc)) {
                        /* there's a write enable bit here that reads as 1 */
                                watchdogreg = CSR_READ_4(sc, DC_WATCHDOG);
                                watchdogreg &= ~DC_WDOG_CTLWREN;
                                watchdogreg |= DC_WDOG_JABBERDIS;
                                CSR_WRITE_4(sc, DC_WATCHDOG, watchdogreg);
                        } else {
                                DC_SETBIT(sc, DC_WATCHDOG, DC_WDOG_JABBERDIS);
                        }
                        DC_CLRBIT(sc, DC_NETCFG, (DC_NETCFG_PCS|
                            DC_NETCFG_PORTSEL|DC_NETCFG_SCRAMBLER));
                        if (sc->dc_type == DC_TYPE_98713)
                                DC_SETBIT(sc, DC_NETCFG, (DC_NETCFG_PCS|
                                    DC_NETCFG_SCRAMBLER));
                        if (!DC_IS_DAVICOM(sc))
                                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_PORTSEL);
                        DC_CLRBIT(sc, DC_10BTCTRL, 0xFFFF);
                        if (DC_IS_INTEL(sc))
                                dc_apply_fixup(sc, IFM_AUTO);
                } else {
                        if (DC_IS_PNIC(sc)) {
                                DC_PN_GPIO_SETBIT(sc, DC_PN_GPIO_SPEEDSEL);
                                DC_PN_GPIO_SETBIT(sc, DC_PN_GPIO_100TX_LOOP);
                                DC_SETBIT(sc, DC_PN_NWAY, DC_PN_NWAY_SPEEDSEL);
                        }
                        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_PORTSEL);
                        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_PCS);
                        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_SCRAMBLER);
                        if (DC_IS_INTEL(sc))
                                dc_apply_fixup(sc,
                                    (media & IFM_GMASK) == IFM_FDX ?
                                    IFM_100_TX|IFM_FDX : IFM_100_TX);
                }
        }

        if (IFM_SUBTYPE(media) == IFM_10_T) {
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_SPEEDSEL);
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_HEARTBEAT);
                if (sc->dc_pmode == DC_PMODE_MII) {
                        int     watchdogreg;

                        /* there's a write enable bit here that reads as 1 */
                        if (DC_IS_INTEL(sc)) {
                                watchdogreg = CSR_READ_4(sc, DC_WATCHDOG);
                                watchdogreg &= ~DC_WDOG_CTLWREN;
                                watchdogreg |= DC_WDOG_JABBERDIS;
                                CSR_WRITE_4(sc, DC_WATCHDOG, watchdogreg);
                        } else {
                                DC_SETBIT(sc, DC_WATCHDOG, DC_WDOG_JABBERDIS);
                        }
                        DC_CLRBIT(sc, DC_NETCFG, (DC_NETCFG_PCS|
                            DC_NETCFG_PORTSEL|DC_NETCFG_SCRAMBLER));
                        if (sc->dc_type == DC_TYPE_98713)
                                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_PCS);
                        if (!DC_IS_DAVICOM(sc))
                                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_PORTSEL);
                        DC_CLRBIT(sc, DC_10BTCTRL, 0xFFFF);
                        if (DC_IS_INTEL(sc))
                                dc_apply_fixup(sc, IFM_AUTO);
                } else {
                        if (DC_IS_PNIC(sc)) {
                                DC_PN_GPIO_CLRBIT(sc, DC_PN_GPIO_SPEEDSEL);
                                DC_PN_GPIO_SETBIT(sc, DC_PN_GPIO_100TX_LOOP);
                                DC_CLRBIT(sc, DC_PN_NWAY, DC_PN_NWAY_SPEEDSEL);
                        }
                        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_PORTSEL);
                        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_PCS);
                        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_SCRAMBLER);
                        if (DC_IS_INTEL(sc)) {
                                DC_CLRBIT(sc, DC_SIARESET, DC_SIA_RESET);
                                DC_CLRBIT(sc, DC_10BTCTRL, 0xFFFF);
                                if ((media & IFM_GMASK) == IFM_FDX)
                                        DC_SETBIT(sc, DC_10BTCTRL, 0x7F3D);
                                else
                                        DC_SETBIT(sc, DC_10BTCTRL, 0x7F3F);
                                DC_SETBIT(sc, DC_SIARESET, DC_SIA_RESET);
                                DC_CLRBIT(sc, DC_10BTCTRL,
                                    DC_TCTL_AUTONEGENBL);
                                dc_apply_fixup(sc,
                                    (media & IFM_GMASK) == IFM_FDX ?
                                    IFM_10_T|IFM_FDX : IFM_10_T);
                                DELAY(20000);
                        }
                }
        }

        /*
         * If this is a Davicom DM9102A card with a DM9801 HomePNA
         * PHY and we want HomePNA mode, set the portsel bit to turn
         * on the external MII port.
         */
        if (DC_IS_DAVICOM(sc)) {
                if (IFM_SUBTYPE(media) == IFM_HPNA_1) {
                        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_PORTSEL);
                        sc->dc_link = 1;
                } else {
                        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_PORTSEL);
                }
        }

        if ((media & IFM_GMASK) == IFM_FDX) {
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_FULLDUPLEX);
                if (sc->dc_pmode == DC_PMODE_SYM && DC_IS_PNIC(sc))
                        DC_SETBIT(sc, DC_PN_NWAY, DC_PN_NWAY_DUPLEX);
        } else {
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_FULLDUPLEX);
                if (sc->dc_pmode == DC_PMODE_SYM && DC_IS_PNIC(sc))
                        DC_CLRBIT(sc, DC_PN_NWAY, DC_PN_NWAY_DUPLEX);
        }

        if (restart)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON|DC_NETCFG_RX_ON);

        return;
}

static void dc_reset(sc)
        struct dc_softc         *sc;
{
        int             i;

        DC_SETBIT(sc, DC_BUSCTL, DC_BUSCTL_RESET);

        for (i = 0; i < DC_TIMEOUT; i++) {
                DELAY(10);
                if (!(CSR_READ_4(sc, DC_BUSCTL) & DC_BUSCTL_RESET))
                        break;
        }

        if (DC_IS_ASIX(sc) || DC_IS_ADMTEK(sc) || DC_IS_CONEXANT(sc)) {
                DELAY(10000);
                DC_CLRBIT(sc, DC_BUSCTL, DC_BUSCTL_RESET);
                i = 0;
        }

        if (i == DC_TIMEOUT)
                if_printf(&sc->arpcom.ac_if, "reset never completed!\n");

        /* Wait a little while for the chip to get its brains in order. */
        DELAY(1000);

        CSR_WRITE_4(sc, DC_IMR, 0x00000000);
        CSR_WRITE_4(sc, DC_BUSCTL, 0x00000000);
        CSR_WRITE_4(sc, DC_NETCFG, 0x00000000);

        /*
         * Bring the SIA out of reset. In some cases, it looks
         * like failing to unreset the SIA soon enough gets it
         * into a state where it will never come out of reset
         * until we reset the whole chip again.
         */
        if (DC_IS_INTEL(sc)) {
                DC_SETBIT(sc, DC_SIARESET, DC_SIA_RESET);
                CSR_WRITE_4(sc, DC_10BTCTRL, 0);
                CSR_WRITE_4(sc, DC_WATCHDOG, 0);
        }

        return;
}

static struct dc_type *dc_devtype(dev)
        device_t                dev;
{
        struct dc_type          *t;
        u_int32_t               rev;

        t = dc_devs;

        while(t->dc_name != NULL) {
                if ((pci_get_vendor(dev) == t->dc_vid) &&
                    (pci_get_device(dev) == t->dc_did)) {
                        /* Check the PCI revision */
                        rev = pci_read_config(dev, DC_PCI_CFRV, 4) & 0xFF;
                        if (t->dc_did == DC_DEVICEID_98713 &&
                            rev >= DC_REVISION_98713A)
                                t++;
                        if (t->dc_did == DC_DEVICEID_98713_CP &&
                            rev >= DC_REVISION_98713A)
                                t++;
                        if (t->dc_did == DC_DEVICEID_987x5 &&
                            rev >= DC_REVISION_98715AEC_C)
                                t++;
                        if (t->dc_did == DC_DEVICEID_987x5 &&
                            rev >= DC_REVISION_98725)
                                t++;
                        if (t->dc_did == DC_DEVICEID_AX88140A &&
                            rev >= DC_REVISION_88141)
                                t++;
                        if (t->dc_did == DC_DEVICEID_82C168 &&
                            rev >= DC_REVISION_82C169)
                                t++;
                        if (t->dc_did == DC_DEVICEID_DM9102 &&
                            rev >= DC_REVISION_DM9102A)
                                t++;
                        return(t);
                }
                t++;
        }

        return(NULL);
}

/*
 * Probe for a 21143 or clone chip. Check the PCI vendor and device
 * IDs against our list and return a device name if we find a match.
 * We do a little bit of extra work to identify the exact type of
 * chip. The MX98713 and MX98713A have the same PCI vendor/device ID,
 * but different revision IDs. The same is true for 98715/98715A
 * chips and the 98725, as well as the ASIX and ADMtek chips. In some
 * cases, the exact chip revision affects driver behavior.
 */
static int dc_probe(dev)
        device_t                dev;
{
        struct dc_type          *t;

        t = dc_devtype(dev);

        if (t != NULL) {
                device_set_desc(dev, t->dc_name);
                return(0);
        }

        return(ENXIO);
}

static void dc_acpi(dev)
        device_t                dev;
{
        u_int32_t               r, cptr;

        /* Find the location of the capabilities block */
        cptr = pci_read_config(dev, DC_PCI_CCAP, 4) & 0xFF;

        r = pci_read_config(dev, cptr, 4) & 0xFF;
        if (r == 0x01) {

                r = pci_read_config(dev, cptr + 4, 4);
                if (r & DC_PSTATE_D3) {
                        u_int32_t               iobase, membase, irq;
                        struct dc_softc         *sc;

                        /* Save important PCI config data. */
                        iobase = pci_read_config(dev, DC_PCI_CFBIO, 4);
                        membase = pci_read_config(dev, DC_PCI_CFBMA, 4);
                        irq = pci_read_config(dev, DC_PCI_CFIT, 4);

                        sc = device_get_softc(dev);
                        /* Reset the power state. */
                        if_printf(&sc->arpcom.ac_if,
                                  "chip is in D%d power mode "
                                  "-- setting to D0\n", r & DC_PSTATE_D3);
                        r &= 0xFFFFFFFC;
                        pci_write_config(dev, cptr + 4, r, 4);

                        /* Restore PCI config data. */
                        pci_write_config(dev, DC_PCI_CFBIO, iobase, 4);
                        pci_write_config(dev, DC_PCI_CFBMA, membase, 4);
                        pci_write_config(dev, DC_PCI_CFIT, irq, 4);
                }
        }
}

static void dc_apply_fixup(sc, media)
        struct dc_softc         *sc;
        int                     media;
{
        struct dc_mediainfo     *m;
        u_int8_t                *p;
        int                     i;
        u_int32_t               reg;

        m = sc->dc_mi;

        while (m != NULL) {
                if (m->dc_media == media)
                        break;
                m = m->dc_next;
        }

        if (m == NULL)
                return;

        for (i = 0, p = m->dc_reset_ptr; i < m->dc_reset_len; i++, p += 2) {
                reg = (p[0] | (p[1] << 8)) << 16;
                CSR_WRITE_4(sc, DC_WATCHDOG, reg);
        }

        for (i = 0, p = m->dc_gp_ptr; i < m->dc_gp_len; i++, p += 2) {
                reg = (p[0] | (p[1] << 8)) << 16;
                CSR_WRITE_4(sc, DC_WATCHDOG, reg);
        }

        return;
}

static void dc_decode_leaf_sia(sc, l)
        struct dc_softc         *sc;
        struct dc_eblock_sia    *l;
{
        struct dc_mediainfo     *m;

        m = malloc(sizeof(struct dc_mediainfo), M_DEVBUF, M_INTWAIT | M_ZERO);
        if (l->dc_sia_code == DC_SIA_CODE_10BT)
                m->dc_media = IFM_10_T;

        if (l->dc_sia_code == DC_SIA_CODE_10BT_FDX)
                m->dc_media = IFM_10_T|IFM_FDX;

        if (l->dc_sia_code == DC_SIA_CODE_10B2)
                m->dc_media = IFM_10_2;

        if (l->dc_sia_code == DC_SIA_CODE_10B5)
                m->dc_media = IFM_10_5;

        m->dc_gp_len = 2;
        m->dc_gp_ptr = (u_int8_t *)&l->dc_sia_gpio_ctl;

        m->dc_next = sc->dc_mi;
        sc->dc_mi = m;

        sc->dc_pmode = DC_PMODE_SIA;

        return;
}

static void dc_decode_leaf_sym(sc, l)
        struct dc_softc         *sc;
        struct dc_eblock_sym    *l;
{
        struct dc_mediainfo     *m;

        m = malloc(sizeof(struct dc_mediainfo), M_DEVBUF, M_INTWAIT | M_ZERO);
        if (l->dc_sym_code == DC_SYM_CODE_100BT)
                m->dc_media = IFM_100_TX;

        if (l->dc_sym_code == DC_SYM_CODE_100BT_FDX)
                m->dc_media = IFM_100_TX|IFM_FDX;

        m->dc_gp_len = 2;
        m->dc_gp_ptr = (u_int8_t *)&l->dc_sym_gpio_ctl;

        m->dc_next = sc->dc_mi;
        sc->dc_mi = m;

        sc->dc_pmode = DC_PMODE_SYM;

        return;
}

static void dc_decode_leaf_mii(sc, l)
        struct dc_softc         *sc;
        struct dc_eblock_mii    *l;
{
        u_int8_t                *p;
        struct dc_mediainfo     *m;

        m = malloc(sizeof(struct dc_mediainfo), M_DEVBUF, M_INTWAIT | M_ZERO);
        /* We abuse IFM_AUTO to represent MII. */
        m->dc_media = IFM_AUTO;
        m->dc_gp_len = l->dc_gpr_len;

        p = (u_int8_t *)l;
        p += sizeof(struct dc_eblock_mii);
        m->dc_gp_ptr = p;
        p += 2 * l->dc_gpr_len;
        m->dc_reset_len = *p;
        p++;
        m->dc_reset_ptr = p;

        m->dc_next = sc->dc_mi;
        sc->dc_mi = m;

        return;
}

static void dc_read_srom(sc, bits)
        struct dc_softc         *sc;
        int                     bits;
{
        int size;

        size = 2 << bits;
        sc->dc_srom = malloc(size, M_DEVBUF, M_INTWAIT);
        dc_read_eeprom(sc, (caddr_t)sc->dc_srom, 0, (size / 2), 0);
}

static void dc_parse_21143_srom(sc)
        struct dc_softc         *sc;
{
        struct dc_leaf_hdr      *lhdr;
        struct dc_eblock_hdr    *hdr;
        int                     i, loff;
        char                    *ptr;
        int                     have_mii;

        have_mii = 0;
        loff = sc->dc_srom[27];
        lhdr = (struct dc_leaf_hdr *)&(sc->dc_srom[loff]);

        ptr = (char *)lhdr;
        ptr += sizeof(struct dc_leaf_hdr) - 1;
        /*
         * Look if we got a MII media block.
         */
        for (i = 0; i < lhdr->dc_mcnt; i++) {
                hdr = (struct dc_eblock_hdr *)ptr;
                if (hdr->dc_type == DC_EBLOCK_MII)
                    have_mii++;

                ptr += (hdr->dc_len & 0x7F);
                ptr++;
        }

        /*
         * Do the same thing again. Only use SIA and SYM media
         * blocks if no MII media block is available.
         */
        ptr = (char *)lhdr;
        ptr += sizeof(struct dc_leaf_hdr) - 1;
        for (i = 0; i < lhdr->dc_mcnt; i++) {
                hdr = (struct dc_eblock_hdr *)ptr;
                switch(hdr->dc_type) {
                case DC_EBLOCK_MII:
                        dc_decode_leaf_mii(sc, (struct dc_eblock_mii *)hdr);
                        break;
                case DC_EBLOCK_SIA:
                        if (! have_mii)
                                dc_decode_leaf_sia(sc,
                                    (struct dc_eblock_sia *)hdr);
                        break;
                case DC_EBLOCK_SYM:
                        if (! have_mii)
                                dc_decode_leaf_sym(sc,
                                    (struct dc_eblock_sym *)hdr);
                        break;
                default:
                        /* Don't care. Yet. */
                        break;
                }
                ptr += (hdr->dc_len & 0x7F);
                ptr++;
        }

        return;
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int dc_attach(dev)
        device_t                dev;
{
        int                     s, tmp = 0;
        u_char                  eaddr[ETHER_ADDR_LEN];
        u_int32_t               command;
        struct dc_softc         *sc;
        struct ifnet            *ifp;
        u_int32_t               revision;
        int                     error = 0, rid, mac_offset;

        s = splimp();

        sc = device_get_softc(dev);
        bzero(sc, sizeof(struct dc_softc));
        callout_init(&sc->dc_stat_timer);

        ifp = &sc->arpcom.ac_if;
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));

        /*
         * Handle power management nonsense.
         */
        dc_acpi(dev);

        /*
         * Map control/status registers.
         */
        command = pci_read_config(dev, PCIR_COMMAND, 4);
        command |= (PCIM_CMD_PORTEN|PCIM_CMD_MEMEN|PCIM_CMD_BUSMASTEREN);
        pci_write_config(dev, PCIR_COMMAND, command, 4);
        command = pci_read_config(dev, PCIR_COMMAND, 4);

#ifdef DC_USEIOSPACE
        if (!(command & PCIM_CMD_PORTEN)) {
                device_printf(dev, "failed to enable I/O ports!\n");
                error = ENXIO;
                goto fail;
        }
#else
        if (!(command & PCIM_CMD_MEMEN)) {
                device_printf(dev, "failed to enable memory mapping!\n");
                error = ENXIO;
                goto fail;
        }
#endif

        rid = DC_RID;
        sc->dc_res = bus_alloc_resource_any(dev, DC_RES, &rid, RF_ACTIVE);

        if (sc->dc_res == NULL) {
                device_printf(dev, "couldn't map ports/memory\n");
                error = ENXIO;
                goto fail;
        }

        sc->dc_btag = rman_get_bustag(sc->dc_res);
        sc->dc_bhandle = rman_get_bushandle(sc->dc_res);

        /* Allocate interrupt */
        rid = 0;
        sc->dc_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
            RF_SHAREABLE | RF_ACTIVE);

        if (sc->dc_irq == NULL) {
                device_printf(dev, "couldn't map interrupt\n");
                bus_release_resource(dev, DC_RES, DC_RID, sc->dc_res);
                error = ENXIO;
                goto fail;
        }

        error = bus_setup_intr(dev, sc->dc_irq, INTR_TYPE_NET,
                               dc_intr, sc, &sc->dc_intrhand, NULL);

        if (error) {
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->dc_irq);
                bus_release_resource(dev, DC_RES, DC_RID, sc->dc_res);
                device_printf(dev, "couldn't set up irq\n");
                goto fail;
        }
        
        /* Need this info to decide on a chip type. */
        sc->dc_info = dc_devtype(dev);
        revision = pci_read_config(dev, DC_PCI_CFRV, 4) & 0x000000FF;

        /* Get the eeprom width, but PNIC has diff eeprom */
        if (sc->dc_info->dc_did != DC_DEVICEID_82C168)
                dc_eeprom_width(sc);

        switch(sc->dc_info->dc_did) {
        case DC_DEVICEID_21143:
                sc->dc_type = DC_TYPE_21143;
                sc->dc_flags |= DC_TX_POLL|DC_TX_USE_TX_INTR;
                sc->dc_flags |= DC_REDUCED_MII_POLL;
                /* Save EEPROM contents so we can parse them later. */
                dc_read_srom(sc, sc->dc_romwidth);
                break;
        case DC_DEVICEID_DM9009:
        case DC_DEVICEID_DM9100:
        case DC_DEVICEID_DM9102:
                sc->dc_type = DC_TYPE_DM9102;
                sc->dc_flags |= DC_TX_COALESCE|DC_TX_INTR_ALWAYS;
                sc->dc_flags |= DC_REDUCED_MII_POLL|DC_TX_STORENFWD;
                sc->dc_pmode = DC_PMODE_MII;
                /* Increase the latency timer value. */
                command = pci_read_config(dev, DC_PCI_CFLT, 4);
                command &= 0xFFFF00FF;
                command |= 0x00008000;
                pci_write_config(dev, DC_PCI_CFLT, command, 4);
                break;
        case DC_DEVICEID_AL981:
                sc->dc_type = DC_TYPE_AL981;
                sc->dc_flags |= DC_TX_USE_TX_INTR;
                sc->dc_flags |= DC_TX_ADMTEK_WAR;
                sc->dc_pmode = DC_PMODE_MII;
                dc_read_srom(sc, sc->dc_romwidth);
                break;
        case DC_DEVICEID_AN985:
        case DC_DEVICEID_EN2242:
        case DC_DEVICEID_3CSOHOB:
                sc->dc_type = DC_TYPE_AN985;
                sc->dc_flags |= DC_64BIT_HASH;
                sc->dc_flags |= DC_TX_USE_TX_INTR;
                sc->dc_flags |= DC_TX_ADMTEK_WAR;
                sc->dc_pmode = DC_PMODE_MII;
                dc_read_srom(sc, sc->dc_romwidth);
                break;
        case DC_DEVICEID_98713:
        case DC_DEVICEID_98713_CP:
                if (revision < DC_REVISION_98713A) {
                        sc->dc_type = DC_TYPE_98713;
                }
                if (revision >= DC_REVISION_98713A) {
                        sc->dc_type = DC_TYPE_98713A;
                        sc->dc_flags |= DC_21143_NWAY;
                }
                sc->dc_flags |= DC_REDUCED_MII_POLL;
                sc->dc_flags |= DC_TX_POLL|DC_TX_USE_TX_INTR;
                break;
        case DC_DEVICEID_987x5:
        case DC_DEVICEID_EN1217:
                /*
                 * Macronix MX98715AEC-C/D/E parts have only a
                 * 128-bit hash table. We need to deal with these
                 * in the same manner as the PNIC II so that we
                 * get the right number of bits out of the
                 * CRC routine.
                 */
                if (revision >= DC_REVISION_98715AEC_C &&
                    revision < DC_REVISION_98725)
                        sc->dc_flags |= DC_128BIT_HASH;
                sc->dc_type = DC_TYPE_987x5;
                sc->dc_flags |= DC_TX_POLL|DC_TX_USE_TX_INTR;
                sc->dc_flags |= DC_REDUCED_MII_POLL|DC_21143_NWAY;
                break;
        case DC_DEVICEID_98727:
                sc->dc_type = DC_TYPE_987x5;
                sc->dc_flags |= DC_TX_POLL|DC_TX_USE_TX_INTR;
                sc->dc_flags |= DC_REDUCED_MII_POLL|DC_21143_NWAY;
                break;
        case DC_DEVICEID_82C115:
                sc->dc_type = DC_TYPE_PNICII;
                sc->dc_flags |= DC_TX_POLL|DC_TX_USE_TX_INTR|DC_128BIT_HASH;
                sc->dc_flags |= DC_REDUCED_MII_POLL|DC_21143_NWAY;
                break;
        case DC_DEVICEID_82C168:
                sc->dc_type = DC_TYPE_PNIC;
                sc->dc_flags |= DC_TX_STORENFWD|DC_TX_INTR_ALWAYS;
                sc->dc_flags |= DC_PNIC_RX_BUG_WAR;
                sc->dc_pnic_rx_buf = malloc(DC_RXLEN * 5, M_DEVBUF, M_WAITOK);
                if (revision < DC_REVISION_82C169)
                        sc->dc_pmode = DC_PMODE_SYM;
                break;
        case DC_DEVICEID_AX88140A:
                sc->dc_type = DC_TYPE_ASIX;
                sc->dc_flags |= DC_TX_USE_TX_INTR|DC_TX_INTR_FIRSTFRAG;
                sc->dc_flags |= DC_REDUCED_MII_POLL;
                sc->dc_pmode = DC_PMODE_MII;
                break;
        case DC_DEVICEID_RS7112:
                sc->dc_type = DC_TYPE_CONEXANT;
                sc->dc_flags |= DC_TX_INTR_ALWAYS;
                sc->dc_flags |= DC_REDUCED_MII_POLL;
                sc->dc_pmode = DC_PMODE_MII;
                dc_read_srom(sc, sc->dc_romwidth);
                break;
        default:
                device_printf(dev, "unknown device: %x\n", sc->dc_info->dc_did);
                break;
        }

        /* Save the cache line size. */
        if (DC_IS_DAVICOM(sc))
                sc->dc_cachesize = 0;
        else
                sc->dc_cachesize = pci_read_config(dev,
                    DC_PCI_CFLT, 4) & 0xFF;

        /* Reset the adapter. */
        dc_reset(sc);

        /* Take 21143 out of snooze mode */
        if (DC_IS_INTEL(sc)) {
                command = pci_read_config(dev, DC_PCI_CFDD, 4);
                command &= ~(DC_CFDD_SNOOZE_MODE|DC_CFDD_SLEEP_MODE);
                pci_write_config(dev, DC_PCI_CFDD, command, 4);
        }

        /*
         * Try to learn something about the supported media.
         * We know that ASIX and ADMtek and Davicom devices
         * will *always* be using MII media, so that's a no-brainer.
         * The tricky ones are the Macronix/PNIC II and the
         * Intel 21143.
         */
        if (DC_IS_INTEL(sc))
                dc_parse_21143_srom(sc);
        else if (DC_IS_MACRONIX(sc) || DC_IS_PNICII(sc)) {
                if (sc->dc_type == DC_TYPE_98713)
                        sc->dc_pmode = DC_PMODE_MII;
                else
                        sc->dc_pmode = DC_PMODE_SYM;
        } else if (!sc->dc_pmode)
                sc->dc_pmode = DC_PMODE_MII;

        /*
         * Get station address from the EEPROM.
         */
        switch(sc->dc_type) {
        case DC_TYPE_98713:
        case DC_TYPE_98713A:
        case DC_TYPE_987x5:
        case DC_TYPE_PNICII:
                dc_read_eeprom(sc, (caddr_t)&mac_offset,
                    (DC_EE_NODEADDR_OFFSET / 2), 1, 0);
                dc_read_eeprom(sc, (caddr_t)&eaddr, (mac_offset / 2), 3, 0);
                break;
        case DC_TYPE_PNIC:
                dc_read_eeprom(sc, (caddr_t)&eaddr, 0, 3, 1);
                break;
        case DC_TYPE_DM9102:
        case DC_TYPE_21143:
        case DC_TYPE_ASIX:
                dc_read_eeprom(sc, (caddr_t)&eaddr, DC_EE_NODEADDR, 3, 0);
                break;
        case DC_TYPE_AL981:
        case DC_TYPE_AN985:
                bcopy(&sc->dc_srom[DC_AL_EE_NODEADDR], (caddr_t)&eaddr,
                    ETHER_ADDR_LEN);
                dc_read_eeprom(sc, (caddr_t)&eaddr, DC_AL_EE_NODEADDR, 3, 0);
                break;
        case DC_TYPE_CONEXANT:
                bcopy(sc->dc_srom + DC_CONEXANT_EE_NODEADDR, &eaddr, 6);
                break;
        default:
                dc_read_eeprom(sc, (caddr_t)&eaddr, DC_EE_NODEADDR, 3, 0);
                break;
        }

        sc->dc_ldata = contigmalloc(sizeof(struct dc_list_data), M_DEVBUF,
            M_NOWAIT, 0, 0xffffffff, PAGE_SIZE, 0);

        if (sc->dc_ldata == NULL) {
                device_printf(dev, "no memory for list buffers!\n");
                if (sc->dc_pnic_rx_buf != NULL)
                        free(sc->dc_pnic_rx_buf, M_DEVBUF);
                bus_teardown_intr(dev, sc->dc_irq, sc->dc_intrhand);
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->dc_irq);
                bus_release_resource(dev, DC_RES, DC_RID, sc->dc_res);
                error = ENXIO;
                goto fail;
        }

        bzero(sc->dc_ldata, sizeof(struct dc_list_data));

        ifp->if_softc = sc;
        ifp->if_mtu = ETHERMTU;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_ioctl = dc_ioctl;
        ifp->if_start = dc_start;
#ifdef DEVICE_POLLING
        ifp->if_poll = dc_poll;
#endif
        ifp->if_watchdog = dc_watchdog;
        ifp->if_init = dc_init;
        ifp->if_baudrate = 10000000;
        ifq_set_maxlen(&ifp->if_snd, DC_TX_LIST_CNT - 1);
        ifq_set_ready(&ifp->if_snd);

        /*
         * Do MII setup. If this is a 21143, check for a PHY on the
         * MII bus after applying any necessary fixups to twiddle the
         * GPIO bits. If we don't end up finding a PHY, restore the
         * old selection (SIA only or SIA/SYM) and attach the dcphy
         * driver instead.
         */
        if (DC_IS_INTEL(sc)) {
                dc_apply_fixup(sc, IFM_AUTO);
                tmp = sc->dc_pmode;
                sc->dc_pmode = DC_PMODE_MII;
        }

        error = mii_phy_probe(dev, &sc->dc_miibus,
            dc_ifmedia_upd, dc_ifmedia_sts);

        if (error && DC_IS_INTEL(sc)) {
                sc->dc_pmode = tmp;
                if (sc->dc_pmode != DC_PMODE_SIA)
                        sc->dc_pmode = DC_PMODE_SYM;
                sc->dc_flags |= DC_21143_NWAY;
                mii_phy_probe(dev, &sc->dc_miibus,
                    dc_ifmedia_upd, dc_ifmedia_sts);
                /*
                 * For non-MII cards, we need to have the 21143
                 * drive the LEDs. Except there are some systems
                 * like the NEC VersaPro NoteBook PC which have no
                 * LEDs, and twiddling these bits has adverse effects
                 * on them. (I.e. you suddenly can't get a link.)
                 */
                if (pci_read_config(dev, DC_PCI_CSID, 4) != 0x80281033)
                        sc->dc_flags |= DC_TULIP_LEDS;
                error = 0;
        }

        if (error) {
                device_printf(dev, "MII without any PHY!\n");
                contigfree(sc->dc_ldata, sizeof(struct dc_list_data),
                    M_DEVBUF);
                if (sc->dc_pnic_rx_buf != NULL)
                        free(sc->dc_pnic_rx_buf, M_DEVBUF);
                bus_teardown_intr(dev, sc->dc_irq, sc->dc_intrhand);
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->dc_irq);
                bus_release_resource(dev, DC_RES, DC_RID, sc->dc_res);
                error = ENXIO;
                goto fail;
        }

        /*
         * Call MI attach routine.
         */
        ether_ifattach(ifp, eaddr);

        if (DC_IS_ADMTEK(sc)) {
                /*
                 * Set automatic TX underrun recovery for the ADMtek chips
                 */
                DC_SETBIT(sc, DC_AL_CR, DC_AL_CR_ATUR);
        }

        /*
         * Tell the upper layer(s) we support long frames.
         */
        ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);

fail:
        splx(s);

        return(error);
}

static int dc_detach(dev)
        device_t                dev;
{
        struct dc_softc         *sc;
        struct ifnet            *ifp;
        int                     s;
        struct dc_mediainfo     *m;

        s = splimp();

        sc = device_get_softc(dev);
        ifp = &sc->arpcom.ac_if;

        dc_stop(sc);
        ether_ifdetach(ifp);

        bus_generic_detach(dev);
        device_delete_child(dev, sc->dc_miibus);

        bus_teardown_intr(dev, sc->dc_irq, sc->dc_intrhand);
        bus_release_resource(dev, SYS_RES_IRQ, 0, sc->dc_irq);
        bus_release_resource(dev, DC_RES, DC_RID, sc->dc_res);

        contigfree(sc->dc_ldata, sizeof(struct dc_list_data), M_DEVBUF);
        if (sc->dc_pnic_rx_buf != NULL)
                free(sc->dc_pnic_rx_buf, M_DEVBUF);

        while(sc->dc_mi != NULL) {
                m = sc->dc_mi->dc_next;
                free(sc->dc_mi, M_DEVBUF);
                sc->dc_mi = m;
        }
        free(sc->dc_srom, M_DEVBUF);

        splx(s);

        return(0);
}

/*
 * Initialize the transmit descriptors.
 */
static int dc_list_tx_init(sc)
        struct dc_softc         *sc;
{
        struct dc_chain_data    *cd;
        struct dc_list_data     *ld;
        int                     i;

        cd = &sc->dc_cdata;
        ld = sc->dc_ldata;
        for (i = 0; i < DC_TX_LIST_CNT; i++) {
                if (i == (DC_TX_LIST_CNT - 1)) {
                        ld->dc_tx_list[i].dc_next =
                            vtophys(&ld->dc_tx_list[0]);
                } else {
                        ld->dc_tx_list[i].dc_next =
                            vtophys(&ld->dc_tx_list[i + 1]);
                }
                cd->dc_tx_chain[i] = NULL;
                ld->dc_tx_list[i].dc_data = 0;
                ld->dc_tx_list[i].dc_ctl = 0;
        }

        cd->dc_tx_prod = cd->dc_tx_cons = cd->dc_tx_cnt = 0;

        return(0);
}


/*
 * Initialize the RX descriptors and allocate mbufs for them. Note that
 * we arrange the descriptors in a closed ring, so that the last descriptor
 * points back to the first.
 */
static int dc_list_rx_init(sc)
        struct dc_softc         *sc;
{
        struct dc_chain_data    *cd;
        struct dc_list_data     *ld;
        int                     i;

        cd = &sc->dc_cdata;
        ld = sc->dc_ldata;

        for (i = 0; i < DC_RX_LIST_CNT; i++) {
                if (dc_newbuf(sc, i, NULL) == ENOBUFS)
                        return(ENOBUFS);
                if (i == (DC_RX_LIST_CNT - 1)) {
                        ld->dc_rx_list[i].dc_next =
                            vtophys(&ld->dc_rx_list[0]);
                } else {
                        ld->dc_rx_list[i].dc_next =
                            vtophys(&ld->dc_rx_list[i + 1]);
                }
        }

        cd->dc_rx_prod = 0;

        return(0);
}

/*
 * Initialize an RX descriptor and attach an MBUF cluster.
 */
static int dc_newbuf(sc, i, m)
        struct dc_softc         *sc;
        int                     i;
        struct mbuf             *m;
{
        struct mbuf             *m_new = NULL;
        struct dc_desc          *c;

        c = &sc->dc_ldata->dc_rx_list[i];

        if (m == NULL) {
                MGETHDR(m_new, MB_DONTWAIT, MT_DATA);
                if (m_new == NULL)
                        return(ENOBUFS);

                MCLGET(m_new, MB_DONTWAIT);
                if (!(m_new->m_flags & M_EXT)) {
                        m_freem(m_new);
                        return(ENOBUFS);
                }
                m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
        } else {
                m_new = m;
                m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
                m_new->m_data = m_new->m_ext.ext_buf;
        }

        m_adj(m_new, sizeof(u_int64_t));

        /*
         * If this is a PNIC chip, zero the buffer. This is part
         * of the workaround for the receive bug in the 82c168 and
         * 82c169 chips.
         */
        if (sc->dc_flags & DC_PNIC_RX_BUG_WAR)
                bzero((char *)mtod(m_new, char *), m_new->m_len);

        sc->dc_cdata.dc_rx_chain[i] = m_new;
        c->dc_data = vtophys(mtod(m_new, caddr_t));
        c->dc_ctl = DC_RXCTL_RLINK | DC_RXLEN;
        c->dc_status = DC_RXSTAT_OWN;

        return(0);
}

/*
 * Grrrrr.
 * The PNIC chip has a terrible bug in it that manifests itself during
 * periods of heavy activity. The exact mode of failure if difficult to
 * pinpoint: sometimes it only happens in promiscuous mode, sometimes it
 * will happen on slow machines. The bug is that sometimes instead of
 * uploading one complete frame during reception, it uploads what looks
 * like the entire contents of its FIFO memory. The frame we want is at
 * the end of the whole mess, but we never know exactly how much data has
 * been uploaded, so salvaging the frame is hard.
 *
 * There is only one way to do it reliably, and it's disgusting.
 * Here's what we know:
 *
 * - We know there will always be somewhere between one and three extra
 *   descriptors uploaded.
 *
 * - We know the desired received frame will always be at the end of the
 *   total data upload.
 *
 * - We know the size of the desired received frame because it will be
 *   provided in the length field of the status word in the last descriptor.
 *
 * Here's what we do:
 *
 * - When we allocate buffers for the receive ring, we bzero() them.
 *   This means that we know that the buffer contents should be all
 *   zeros, except for data uploaded by the chip.
 *
 * - We also force the PNIC chip to upload frames that include the
 *   ethernet CRC at the end.
 *
 * - We gather all of the bogus frame data into a single buffer.
 *
 * - We then position a pointer at the end of this buffer and scan
 *   backwards until we encounter the first non-zero byte of data.
 *   This is the end of the received frame. We know we will encounter
 *   some data at the end of the frame because the CRC will always be
 *   there, so even if the sender transmits a packet of all zeros,
 *   we won't be fooled.
 *
 * - We know the size of the actual received frame, so we subtract
 *   that value from the current pointer location. This brings us
 *   to the start of the actual received packet.
 *
 * - We copy this into an mbuf and pass it on, along with the actual
 *   frame length.
 *
 * The performance hit is tremendous, but it beats dropping frames all
 * the time.
 */

#define DC_WHOLEFRAME   (DC_RXSTAT_FIRSTFRAG|DC_RXSTAT_LASTFRAG)
static void dc_pnic_rx_bug_war(sc, idx)
        struct dc_softc         *sc;
        int                     idx;
{
        struct dc_desc          *cur_rx;
        struct dc_desc          *c = NULL;
        struct mbuf             *m = NULL;
        unsigned char           *ptr;
        int                     i, total_len;
        u_int32_t               rxstat = 0;

        i = sc->dc_pnic_rx_bug_save;
        cur_rx = &sc->dc_ldata->dc_rx_list[idx];
        ptr = sc->dc_pnic_rx_buf;
        bzero(ptr, DC_RXLEN * 5);

        /* Copy all the bytes from the bogus buffers. */
        while (1) {
                c = &sc->dc_ldata->dc_rx_list[i];
                rxstat = c->dc_status;
                m = sc->dc_cdata.dc_rx_chain[i];
                bcopy(mtod(m, char *), ptr, DC_RXLEN);
                ptr += DC_RXLEN;
                /* If this is the last buffer, break out. */
                if (i == idx || rxstat & DC_RXSTAT_LASTFRAG)
                        break;
                dc_newbuf(sc, i, m);
                DC_INC(i, DC_RX_LIST_CNT);
        }

        /* Find the length of the actual receive frame. */
        total_len = DC_RXBYTES(rxstat);

        /* Scan backwards until we hit a non-zero byte. */
        while(*ptr == 0x00)
                ptr--;

        /* Round off. */
        if ((uintptr_t)(ptr) & 0x3)
                ptr -= 1;

        /* Now find the start of the frame. */
        ptr -= total_len;
        if (ptr < sc->dc_pnic_rx_buf)
                ptr = sc->dc_pnic_rx_buf;

        /*
         * Now copy the salvaged frame to the last mbuf and fake up
         * the status word to make it look like a successful
         * frame reception.
         */
        dc_newbuf(sc, i, m);
        bcopy(ptr, mtod(m, char *), total_len); 
        cur_rx->dc_status = rxstat | DC_RXSTAT_FIRSTFRAG;

        return;
}

/*
 * This routine searches the RX ring for dirty descriptors in the
 * event that the rxeof routine falls out of sync with the chip's
 * current descriptor pointer. This may happen sometimes as a result
 * of a "no RX buffer available" condition that happens when the chip
 * consumes all of the RX buffers before the driver has a chance to
 * process the RX ring. This routine may need to be called more than
 * once to bring the driver back in sync with the chip, however we
 * should still be getting RX DONE interrupts to drive the search
 * for new packets in the RX ring, so we should catch up eventually.
 */
static int dc_rx_resync(sc)
        struct dc_softc         *sc;
{
        int                     i, pos;
        struct dc_desc          *cur_rx;

        pos = sc->dc_cdata.dc_rx_prod;

        for (i = 0; i < DC_RX_LIST_CNT; i++) {
                cur_rx = &sc->dc_ldata->dc_rx_list[pos];
                if (!(cur_rx->dc_status & DC_RXSTAT_OWN))
                        break;
                DC_INC(pos, DC_RX_LIST_CNT);
        }

        /* If the ring really is empty, then just return. */
        if (i == DC_RX_LIST_CNT)
                return(0);

        /* We've fallen behing the chip: catch it. */
        sc->dc_cdata.dc_rx_prod = pos;

        return(EAGAIN);
}

/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static void dc_rxeof(sc)
        struct dc_softc         *sc;
{
        struct mbuf             *m;
        struct ifnet            *ifp;
        struct dc_desc          *cur_rx;
        int                     i, total_len = 0;
        u_int32_t               rxstat;

        ifp = &sc->arpcom.ac_if;
        i = sc->dc_cdata.dc_rx_prod;

        while(!(sc->dc_ldata->dc_rx_list[i].dc_status & DC_RXSTAT_OWN)) {

#ifdef DEVICE_POLLING
                if (ifp->if_flags & IFF_POLLING) {
                        if (sc->rxcycles <= 0)
                                break;
                        sc->rxcycles--;
                }
#endif /* DEVICE_POLLING */
                cur_rx = &sc->dc_ldata->dc_rx_list[i];
                rxstat = cur_rx->dc_status;
                m = sc->dc_cdata.dc_rx_chain[i];
                total_len = DC_RXBYTES(rxstat);

                if (sc->dc_flags & DC_PNIC_RX_BUG_WAR) {
                        if ((rxstat & DC_WHOLEFRAME) != DC_WHOLEFRAME) {
                                if (rxstat & DC_RXSTAT_FIRSTFRAG)
                                        sc->dc_pnic_rx_bug_save = i;
                                if ((rxstat & DC_RXSTAT_LASTFRAG) == 0) {
                                        DC_INC(i, DC_RX_LIST_CNT);
                                        continue;
                                }
                                dc_pnic_rx_bug_war(sc, i);
                                rxstat = cur_rx->dc_status;
                                total_len = DC_RXBYTES(rxstat);
                        }
                }

                sc->dc_cdata.dc_rx_chain[i] = NULL;

                /*
                 * If an error occurs, update stats, clear the
                 * status word and leave the mbuf cluster in place:
                 * it should simply get re-used next time this descriptor
                 * comes up in the ring.  However, don't report long
                 * frames as errors since they could be vlans
                 */
                if ((rxstat & DC_RXSTAT_RXERR)){ 
                        if (!(rxstat & DC_RXSTAT_GIANT) ||
                            (rxstat & (DC_RXSTAT_CRCERR | DC_RXSTAT_DRIBBLE |
                                       DC_RXSTAT_MIIERE | DC_RXSTAT_COLLSEEN |
                                       DC_RXSTAT_RUNT   | DC_RXSTAT_DE))) {
                                ifp->if_ierrors++;
                                if (rxstat & DC_RXSTAT_COLLSEEN)
                                        ifp->if_collisions++;
                                dc_newbuf(sc, i, m);
                                if (rxstat & DC_RXSTAT_CRCERR) {
                                        DC_INC(i, DC_RX_LIST_CNT);
                                        continue;
                                } else {
                                        dc_init(sc);
                                        return;
                                }
                        }
                }

                /* No errors; receive the packet. */    
                total_len -= ETHER_CRC_LEN;

#ifdef __i386__
                /*
                 * On the x86 we do not have alignment problems, so try to
                 * allocate a new buffer for the receive ring, and pass up
                 * the one where the packet is already, saving the expensive
                 * copy done in m_devget().
                 * If we are on an architecture with alignment problems, or
                 * if the allocation fails, then use m_devget and leave the
                 * existing buffer in the receive ring.
                 */
                if (dc_quick && dc_newbuf(sc, i, NULL) == 0) {
                        m->m_pkthdr.rcvif = ifp;
                        m->m_pkthdr.len = m->m_len = total_len;
                        DC_INC(i, DC_RX_LIST_CNT);
                } else
#endif
                {
                        struct mbuf *m0;

                        m0 = m_devget(mtod(m, char *) - ETHER_ALIGN,
                            total_len + ETHER_ALIGN, 0, ifp, NULL);
                        dc_newbuf(sc, i, m);
                        DC_INC(i, DC_RX_LIST_CNT);
                        if (m0 == NULL) {
                                ifp->if_ierrors++;
                                continue;
                        }
                        m_adj(m0, ETHER_ALIGN);
                        m = m0;
                }

                ifp->if_ipackets++;
                (*ifp->if_input)(ifp, m);
        }

        sc->dc_cdata.dc_rx_prod = i;
}

/*
 * A frame was downloaded to the chip. It's safe for us to clean up
 * the list buffers.
 */

static void
dc_txeof(sc)
        struct dc_softc         *sc;
{
        struct dc_desc          *cur_tx = NULL;
        struct ifnet            *ifp;
        int                     idx;

        ifp = &sc->arpcom.ac_if;

        /*
         * Go through our tx list and free mbufs for those
         * frames that have been transmitted.
         */
        idx = sc->dc_cdata.dc_tx_cons;
        while(idx != sc->dc_cdata.dc_tx_prod) {
                u_int32_t               txstat;

                cur_tx = &sc->dc_ldata->dc_tx_list[idx];
                txstat = cur_tx->dc_status;

                if (txstat & DC_TXSTAT_OWN)
                        break;

                if (!(cur_tx->dc_ctl & DC_TXCTL_LASTFRAG) ||
                    cur_tx->dc_ctl & DC_TXCTL_SETUP) {
                        if (cur_tx->dc_ctl & DC_TXCTL_SETUP) {
                                /*
                                 * Yes, the PNIC is so brain damaged
                                 * that it will sometimes generate a TX
                                 * underrun error while DMAing the RX
                                 * filter setup frame. If we detect this,
                                 * we have to send the setup frame again,
                                 * or else the filter won't be programmed
                                 * correctly.
                                 */
                                if (DC_IS_PNIC(sc)) {
                                        if (txstat & DC_TXSTAT_ERRSUM)
                                                dc_setfilt(sc);
                                }
                                sc->dc_cdata.dc_tx_chain[idx] = NULL;
                        }
                        sc->dc_cdata.dc_tx_cnt--;
                        DC_INC(idx, DC_TX_LIST_CNT);
                        continue;
                }

                if (DC_IS_CONEXANT(sc)) {
                        /*
                         * For some reason Conexant chips like
                         * setting the CARRLOST flag even when
                         * the carrier is there. In CURRENT we
                         * have the same problem for Xircom
                         * cards !
                         */
                        if (/*sc->dc_type == DC_TYPE_21143 &&*/
                            sc->dc_pmode == DC_PMODE_MII &&
                            ((txstat & 0xFFFF) & ~(DC_TXSTAT_ERRSUM|
                            DC_TXSTAT_NOCARRIER)))
                                txstat &= ~DC_TXSTAT_ERRSUM;
                } else {
                        if (/*sc->dc_type == DC_TYPE_21143 &&*/
                            sc->dc_pmode == DC_PMODE_MII &&
                            ((txstat & 0xFFFF) & ~(DC_TXSTAT_ERRSUM|
                            DC_TXSTAT_NOCARRIER|DC_TXSTAT_CARRLOST)))
                                txstat &= ~DC_TXSTAT_ERRSUM;
                }

                if (txstat & DC_TXSTAT_ERRSUM) {
                        ifp->if_oerrors++;
                        if (txstat & DC_TXSTAT_EXCESSCOLL)
                                ifp->if_collisions++;
                        if (txstat & DC_TXSTAT_LATECOLL)
                                ifp->if_collisions++;
                        if (!(txstat & DC_TXSTAT_UNDERRUN)) {
                                dc_init(sc);
                                return;
                        }
                }

                ifp->if_collisions += (txstat & DC_TXSTAT_COLLCNT) >> 3;

                ifp->if_opackets++;
                if (sc->dc_cdata.dc_tx_chain[idx] != NULL) {
                        m_freem(sc->dc_cdata.dc_tx_chain[idx]);
                        sc->dc_cdata.dc_tx_chain[idx] = NULL;
                }

                sc->dc_cdata.dc_tx_cnt--;
                DC_INC(idx, DC_TX_LIST_CNT);
        }

        if (idx != sc->dc_cdata.dc_tx_cons) {
                /* some buffers have been freed */
                sc->dc_cdata.dc_tx_cons = idx;
                ifp->if_flags &= ~IFF_OACTIVE;
        }
        ifp->if_timer = (sc->dc_cdata.dc_tx_cnt == 0) ? 0 : 5;

        return;
}

static void dc_tick(xsc)
        void                    *xsc;
{
        struct dc_softc         *sc;
        struct mii_data         *mii;
        struct ifnet            *ifp;
        int                     s;
        u_int32_t               r;

        s = splimp();

        sc = xsc;
        ifp = &sc->arpcom.ac_if;
        mii = device_get_softc(sc->dc_miibus);

        if (sc->dc_flags & DC_REDUCED_MII_POLL) {
                if (sc->dc_flags & DC_21143_NWAY) {
                        r = CSR_READ_4(sc, DC_10BTSTAT);
                        if (IFM_SUBTYPE(mii->mii_media_active) ==
                            IFM_100_TX && (r & DC_TSTAT_LS100)) {
                                sc->dc_link = 0;
                                mii_mediachg(mii);
                        }
                        if (IFM_SUBTYPE(mii->mii_media_active) ==
                            IFM_10_T && (r & DC_TSTAT_LS10)) {
                                sc->dc_link = 0;
                                mii_mediachg(mii);
                        }
                        if (sc->dc_link == 0)
                                mii_tick(mii);
                } else {
                        r = CSR_READ_4(sc, DC_ISR);
                        if ((r & DC_ISR_RX_STATE) == DC_RXSTATE_WAIT &&
                            sc->dc_cdata.dc_tx_cnt == 0)
                                mii_tick(mii);
                                if (!(mii->mii_media_status & IFM_ACTIVE))
                                        sc->dc_link = 0;
                }
        } else
                mii_tick(mii);

        /*
         * When the init routine completes, we expect to be able to send
         * packets right away, and in fact the network code will send a
         * gratuitous ARP the moment the init routine marks the interface
         * as running. However, even though the MAC may have been initialized,
         * there may be a delay of a few seconds before the PHY completes
         * autonegotiation and the link is brought up. Any transmissions
         * made during that delay will be lost. Dealing with this is tricky:
         * we can't just pause in the init routine while waiting for the
         * PHY to come ready since that would bring the whole system to
         * a screeching halt for several seconds.
         *
         * What we do here is prevent the TX start routine from sending
         * any packets until a link has been established. After the
         * interface has been initialized, the tick routine will poll
         * the state of the PHY until the IFM_ACTIVE flag is set. Until
         * that time, packets will stay in the send queue, and once the
         * link comes up, they will be flushed out to the wire.
         */
        if (!sc->dc_link) {
                mii_pollstat(mii);
                if (mii->mii_media_status & IFM_ACTIVE &&
                    IFM_SUBTYPE(mii->mii_media_active) != IFM_NONE) {
                        sc->dc_link++;
                        if (!ifq_is_empty(&ifp->if_snd))
                                dc_start(ifp);
                }
        }

        if (sc->dc_flags & DC_21143_NWAY && !sc->dc_link)
                callout_reset(&sc->dc_stat_timer, hz / 10, dc_tick, sc);
        else
                callout_reset(&sc->dc_stat_timer, hz, dc_tick, sc);

        splx(s);

        return;
}

/*
 * A transmit underrun has occurred.  Back off the transmit threshold,
 * or switch to store and forward mode if we have to.
 */
static void dc_tx_underrun(sc)
        struct dc_softc         *sc;
{
        u_int32_t               isr;
        int                     i;

        if (DC_IS_DAVICOM(sc))
                dc_init(sc);

        if (DC_IS_INTEL(sc)) {
                /*
                 * The real 21143 requires that the transmitter be idle
                 * in order to change the transmit threshold or store
                 * and forward state.
                 */
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON);

                for (i = 0; i < DC_TIMEOUT; i++) {
                        isr = CSR_READ_4(sc, DC_ISR);
                        if (isr & DC_ISR_TX_IDLE)
                                break;
                        DELAY(10);
                }
                if (i == DC_TIMEOUT) {
                        if_printf(&sc->arpcom.ac_if,
                                  "failed to force tx to idle state\n");
                        dc_init(sc);
                }
        }

        if_printf(&sc->arpcom.ac_if, "TX underrun -- ");
        sc->dc_txthresh += DC_TXTHRESH_INC;
        if (sc->dc_txthresh > DC_TXTHRESH_MAX) {
                printf("using store and forward mode\n");
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_STORENFWD);
        } else {
                printf("increasing TX threshold\n");
                DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_TX_THRESH);
                DC_SETBIT(sc, DC_NETCFG, sc->dc_txthresh);
        }

        if (DC_IS_INTEL(sc))
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON);

        return;
}

#ifdef DEVICE_POLLING

static void
dc_poll(struct ifnet *ifp, enum poll_cmd cmd, int count)
{
        struct  dc_softc *sc = ifp->if_softc;
        u_int32_t status;

        switch(cmd) {
        case POLL_REGISTER:
                /* Disable interrupts */
                CSR_WRITE_4(sc, DC_IMR, 0x00000000);
                break;
        case POLL_DEREGISTER:
                /* Re-enable interrupts. */
                CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
                break;
        case POLL_ONLY:
                sc->rxcycles = count;
                dc_rxeof(sc);
                dc_txeof(sc);
                if ((ifp->if_flags & IFF_OACTIVE) == 0 && !ifq_is_empty(&ifp->if_snd))
                        dc_start(ifp);
                break;
        case POLL_AND_CHECK_STATUS:
                sc->rxcycles = count;
                dc_rxeof(sc);
                dc_txeof(sc);
                if ((ifp->if_flags & IFF_OACTIVE) == 0 && !ifq_is_empty(&ifp->if_snd))
                        dc_start(ifp);
                status = CSR_READ_4(sc, DC_ISR);
                status &= (DC_ISR_RX_WATDOGTIMEO|DC_ISR_RX_NOBUF|
                        DC_ISR_TX_NOBUF|DC_ISR_TX_IDLE|DC_ISR_TX_UNDERRUN|
                        DC_ISR_BUS_ERR);
                if (!status)
                        break;
                /* ack what we have */
                CSR_WRITE_4(sc, DC_ISR, status);

                if (status & (DC_ISR_RX_WATDOGTIMEO|DC_ISR_RX_NOBUF) ) {
                        u_int32_t r = CSR_READ_4(sc, DC_FRAMESDISCARDED);
                        ifp->if_ierrors += (r & 0xffff) + ((r >> 17) & 0x7ff);

                        if (dc_rx_resync(sc))
                                dc_rxeof(sc);
                }
                /* restart transmit unit if necessary */
                if (status & DC_ISR_TX_IDLE && sc->dc_cdata.dc_tx_cnt)
                        CSR_WRITE_4(sc, DC_TXSTART, 0xFFFFFFFF);

                if (status & DC_ISR_TX_UNDERRUN)
                        dc_tx_underrun(sc);

                if (status & DC_ISR_BUS_ERR) {
                        if_printf(ifp, "dc_poll: bus error\n");
                        dc_reset(sc);
                        dc_init(sc);
                }
                break;
        }
}
#endif /* DEVICE_POLLING */

static void dc_intr(arg)
        void                    *arg;
{
        struct dc_softc         *sc;
        struct ifnet            *ifp;
        u_int32_t               status;

        sc = arg;

        if (sc->suspended) {
                return;
        }

        ifp = &sc->arpcom.ac_if;

        if ( (CSR_READ_4(sc, DC_ISR) & DC_INTRS) == 0)
                return ;

        /* Suppress unwanted interrupts */
        if (!(ifp->if_flags & IFF_UP)) {
                if (CSR_READ_4(sc, DC_ISR) & DC_INTRS)
                        dc_stop(sc);
                return;
        }

        /* Disable interrupts. */
        CSR_WRITE_4(sc, DC_IMR, 0x00000000);

        while((status = CSR_READ_4(sc, DC_ISR)) & DC_INTRS) {

                CSR_WRITE_4(sc, DC_ISR, status);

                if (status & DC_ISR_RX_OK) {
                        int             curpkts;
                        curpkts = ifp->if_ipackets;
                        dc_rxeof(sc);
                        if (curpkts == ifp->if_ipackets) {
                                while(dc_rx_resync(sc))
                                        dc_rxeof(sc);
                        }
                }

                if (status & (DC_ISR_TX_OK|DC_ISR_TX_NOBUF))
                        dc_txeof(sc);

                if (status & DC_ISR_TX_IDLE) {
                        dc_txeof(sc);
                        if (sc->dc_cdata.dc_tx_cnt) {
                                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON);
                                CSR_WRITE_4(sc, DC_TXSTART, 0xFFFFFFFF);
                        }
                }

                if (status & DC_ISR_TX_UNDERRUN)
                        dc_tx_underrun(sc);

                if ((status & DC_ISR_RX_WATDOGTIMEO)
                    || (status & DC_ISR_RX_NOBUF)) {
                        int             curpkts;
                        curpkts = ifp->if_ipackets;
                        dc_rxeof(sc);
                        if (curpkts == ifp->if_ipackets) {
                                while(dc_rx_resync(sc))
                                        dc_rxeof(sc);
                        }
                }

                if (status & DC_ISR_BUS_ERR) {
                        dc_reset(sc);
                        dc_init(sc);
                }
        }

        /* Re-enable interrupts. */
        CSR_WRITE_4(sc, DC_IMR, DC_INTRS);

        if (!ifq_is_empty(&ifp->if_snd))
                dc_start(ifp);

        return;
}

/*
 * Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
 * pointers to the fragment pointers.
 */
static int dc_encap(sc, m_head, txidx)
        struct dc_softc         *sc;
        struct mbuf             *m_head;
        u_int32_t               *txidx;
{
        struct dc_desc          *f = NULL;
        struct mbuf             *m;
        int                     frag, cur, cnt = 0;

        /*
         * Start packing the mbufs in this chain into
         * the fragment pointers. Stop when we run out
         * of fragments or hit the end of the mbuf chain.
         */
        m = m_head;
        cur = frag = *txidx;

        for (m = m_head; m != NULL; m = m->m_next) {
                if (m->m_len != 0) {
                        if (sc->dc_flags & DC_TX_ADMTEK_WAR) {
                                if (*txidx != sc->dc_cdata.dc_tx_prod &&
                                    frag == (DC_TX_LIST_CNT - 1))
                                        return(ENOBUFS);
                        }
                        if ((DC_TX_LIST_CNT -
                            (sc->dc_cdata.dc_tx_cnt + cnt)) < 5)
                                return(ENOBUFS);

                        f = &sc->dc_ldata->dc_tx_list[frag];
                        f->dc_ctl = DC_TXCTL_TLINK | m->m_len;
                        if (cnt == 0) {
                                f->dc_status = 0;
                                f->dc_ctl |= DC_TXCTL_FIRSTFRAG;
                        } else
                                f->dc_status = DC_TXSTAT_OWN;
                        f->dc_data = vtophys(mtod(m, vm_offset_t));
                        cur = frag;
                        DC_INC(frag, DC_TX_LIST_CNT);
                        cnt++;
                }
        }

        if (m != NULL)
                return(ENOBUFS);

        sc->dc_cdata.dc_tx_cnt += cnt;
        sc->dc_cdata.dc_tx_chain[cur] = m_head;
        sc->dc_ldata->dc_tx_list[cur].dc_ctl |= DC_TXCTL_LASTFRAG;
        if (sc->dc_flags & DC_TX_INTR_FIRSTFRAG)
                sc->dc_ldata->dc_tx_list[*txidx].dc_ctl |= DC_TXCTL_FINT;
        if (sc->dc_flags & DC_TX_INTR_ALWAYS)
                sc->dc_ldata->dc_tx_list[cur].dc_ctl |= DC_TXCTL_FINT;
        if (sc->dc_flags & DC_TX_USE_TX_INTR && sc->dc_cdata.dc_tx_cnt > 64)
                sc->dc_ldata->dc_tx_list[cur].dc_ctl |= DC_TXCTL_FINT;
        sc->dc_ldata->dc_tx_list[*txidx].dc_status = DC_TXSTAT_OWN;
        *txidx = frag;

        return(0);
}

/*
 * Main transmit routine. To avoid having to do mbuf copies, we put pointers
 * to the mbuf data regions directly in the transmit lists. We also save a
 * copy of the pointers since the transmit list fragment pointers are
 * physical addresses.
 */

static void dc_start(ifp)
        struct ifnet            *ifp;
{
        struct dc_softc         *sc;
        struct mbuf *m_head = NULL, *m_new;
        int did_defrag, idx;

        sc = ifp->if_softc;

        if (!sc->dc_link)
                return;

        if (ifp->if_flags & IFF_OACTIVE)
                return;

        idx = sc->dc_cdata.dc_tx_prod;

        while(sc->dc_cdata.dc_tx_chain[idx] == NULL) {
                did_defrag = 0;
                m_head = ifq_poll(&ifp->if_snd);
                if (m_head == NULL)
                        break;

                if (sc->dc_flags & DC_TX_COALESCE &&
                    m_head->m_next != NULL) {
                        /*
                         * Check first if coalescing allows us to queue
                         * the packet. We don't want to loose it if
                         * the TX queue is full.
                         */ 
                        if ((sc->dc_flags & DC_TX_ADMTEK_WAR) &&
                            idx != sc->dc_cdata.dc_tx_prod &&
                            idx == (DC_TX_LIST_CNT - 1)) {
                                ifp->if_flags |= IFF_OACTIVE;
                                break;
                        }
                        if ((DC_TX_LIST_CNT - sc->dc_cdata.dc_tx_cnt) < 5) {
                                ifp->if_flags |= IFF_OACTIVE;
                                break;
                        }

                        /* only coalesce if have >1 mbufs */
                        m_new = m_defrag_nofree(m_head, MB_DONTWAIT);
                        if (m_new == NULL) {
                                ifp->if_flags |= IFF_OACTIVE;
                                break;
                        }
                        m_freem(m_head);
                        m_head = m_new;
                        did_defrag = 1;
                }

                if (dc_encap(sc, m_head, &idx)) {
                        if (did_defrag) {
                                m_freem(m_head);
                                m_new = ifq_dequeue(&ifp->if_snd);
                                m_freem(m_new);
                        }
                        ifp->if_flags |= IFF_OACTIVE;
                        break;
                }

                m_new = ifq_dequeue(&ifp->if_snd);
                if (did_defrag)
                        m_freem(m_new);

                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                BPF_MTAP(ifp, m_head);

                if (sc->dc_flags & DC_TX_ONE) {
                        ifp->if_flags |= IFF_OACTIVE;
                        break;
                }
        }

        /* Transmit */
        sc->dc_cdata.dc_tx_prod = idx;
        if (!(sc->dc_flags & DC_TX_POLL))
                CSR_WRITE_4(sc, DC_TXSTART, 0xFFFFFFFF);

        /*
         * Set a timeout in case the chip goes out to lunch.
         */
        ifp->if_timer = 5;

        return;
}

static void dc_init(xsc)
        void                    *xsc;
{
        struct dc_softc         *sc = xsc;
        struct ifnet            *ifp = &sc->arpcom.ac_if;
        struct mii_data         *mii;
        int                     s;

        s = splimp();

        mii = device_get_softc(sc->dc_miibus);

        /*
         * Cancel pending I/O and free all RX/TX buffers.
         */
        dc_stop(sc);
        dc_reset(sc);

        /*
         * Set cache alignment and burst length.
         */
        if (DC_IS_ASIX(sc) || DC_IS_DAVICOM(sc))
                CSR_WRITE_4(sc, DC_BUSCTL, 0);
        else
                CSR_WRITE_4(sc, DC_BUSCTL, DC_BUSCTL_MRME|DC_BUSCTL_MRLE);
        /*
         * Evenly share the bus between receive and transmit process.
         */
        if (DC_IS_INTEL(sc))
                DC_SETBIT(sc, DC_BUSCTL, DC_BUSCTL_ARBITRATION);
        if (DC_IS_DAVICOM(sc) || DC_IS_INTEL(sc)) {
                DC_SETBIT(sc, DC_BUSCTL, DC_BURSTLEN_USECA);
        } else {
                DC_SETBIT(sc, DC_BUSCTL, DC_BURSTLEN_16LONG);
        }
        if (sc->dc_flags & DC_TX_POLL)
                DC_SETBIT(sc, DC_BUSCTL, DC_TXPOLL_1);
        switch(sc->dc_cachesize) {
        case 32:
                DC_SETBIT(sc, DC_BUSCTL, DC_CACHEALIGN_32LONG);
                break;
        case 16:
                DC_SETBIT(sc, DC_BUSCTL, DC_CACHEALIGN_16LONG);
                break; 
        case 8:
                DC_SETBIT(sc, DC_BUSCTL, DC_CACHEALIGN_8LONG);
                break;  
        case 0:
        default:
                DC_SETBIT(sc, DC_BUSCTL, DC_CACHEALIGN_NONE);
                break;
        }

        if (sc->dc_flags & DC_TX_STORENFWD)
                DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_STORENFWD);
        else {
                if (sc->dc_txthresh > DC_TXTHRESH_MAX) {
                        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_STORENFWD);
                } else {
                        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_STORENFWD);
                        DC_SETBIT(sc, DC_NETCFG, sc->dc_txthresh);
                }
        }

        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_NO_RXCRC);
        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_TX_BACKOFF);

        if (DC_IS_MACRONIX(sc) || DC_IS_PNICII(sc)) {
                /*
                 * The app notes for the 98713 and 98715A say that
                 * in order to have the chips operate properly, a magic
                 * number must be written to CSR16. Macronix does not
                 * document the meaning of these bits so there's no way
                 * to know exactly what they do. The 98713 has a magic
                 * number all its own; the rest all use a different one.
                 */
                DC_CLRBIT(sc, DC_MX_MAGICPACKET, 0xFFFF0000);
                if (sc->dc_type == DC_TYPE_98713)
                        DC_SETBIT(sc, DC_MX_MAGICPACKET, DC_MX_MAGIC_98713);
                else
                        DC_SETBIT(sc, DC_MX_MAGICPACKET, DC_MX_MAGIC_98715);
        }

        DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_TX_THRESH);
        DC_SETBIT(sc, DC_NETCFG, DC_TXTHRESH_MIN);

        /* Init circular RX list. */
        if (dc_list_rx_init(sc) == ENOBUFS) {
                if_printf(ifp, "initialization failed: no "
                          "memory for rx buffers\n");
                dc_stop(sc);
                (void)splx(s);
                return;
        }

        /*
         * Init tx descriptors.
         */
        dc_list_tx_init(sc);

        /*
         * Load the address of the RX list.
         */
        CSR_WRITE_4(sc, DC_RXADDR, vtophys(&sc->dc_ldata->dc_rx_list[0]));
        CSR_WRITE_4(sc, DC_TXADDR, vtophys(&sc->dc_ldata->dc_tx_list[0]));

        /*
         * Enable interrupts.
         */
#ifdef DEVICE_POLLING
        /*
         * ... but only if we are not polling, and make sure they are off in
         * the case of polling. Some cards (e.g. fxp) turn interrupts on
         * after a reset.
         */
        if (ifp->if_flags & IFF_POLLING)
                CSR_WRITE_4(sc, DC_IMR, 0x00000000);
        else
#endif
        CSR_WRITE_4(sc, DC_IMR, DC_INTRS);
        CSR_WRITE_4(sc, DC_ISR, 0xFFFFFFFF);

        /* Enable transmitter. */
        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON);

        /*
         * If this is an Intel 21143 and we're not using the
         * MII port, program the LED control pins so we get
         * link and activity indications.
         */
        if (sc->dc_flags & DC_TULIP_LEDS) {
                CSR_WRITE_4(sc, DC_WATCHDOG,
                    DC_WDOG_CTLWREN|DC_WDOG_LINK|DC_WDOG_ACTIVITY);   
                CSR_WRITE_4(sc, DC_WATCHDOG, 0);
        }

        /*
         * Load the RX/multicast filter. We do this sort of late
         * because the filter programming scheme on the 21143 and
         * some clones requires DMAing a setup frame via the TX
         * engine, and we need the transmitter enabled for that.
         */
        dc_setfilt(sc);

        /* Enable receiver. */
        DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_RX_ON);
        CSR_WRITE_4(sc, DC_RXSTART, 0xFFFFFFFF);

        mii_mediachg(mii);
        dc_setcfg(sc, sc->dc_if_media);

        ifp->if_flags |= IFF_RUNNING;
        ifp->if_flags &= ~IFF_OACTIVE;

        (void)splx(s);

        /* Don't start the ticker if this is a homePNA link. */
        if (IFM_SUBTYPE(mii->mii_media.ifm_media) == IFM_HPNA_1)
                sc->dc_link = 1;
        else {
                if (sc->dc_flags & DC_21143_NWAY)
                        callout_reset(&sc->dc_stat_timer, hz/10, dc_tick, sc);
                else
                        callout_reset(&sc->dc_stat_timer, hz, dc_tick, sc);
        }

        return;
}

/*
 * Set media options.
 */
static int dc_ifmedia_upd(ifp)
        struct ifnet            *ifp;
{
        struct dc_softc         *sc;
        struct mii_data         *mii;
        struct ifmedia          *ifm;

        sc = ifp->if_softc;
        mii = device_get_softc(sc->dc_miibus);
        mii_mediachg(mii);
        ifm = &mii->mii_media;

        if (DC_IS_DAVICOM(sc) &&
            IFM_SUBTYPE(ifm->ifm_media) == IFM_HPNA_1)
                dc_setcfg(sc, ifm->ifm_media);
        else
                sc->dc_link = 0;

        return(0);
}

/*
 * Report current media status.
 */
static void dc_ifmedia_sts(ifp, ifmr)
        struct ifnet            *ifp;
        struct ifmediareq       *ifmr;
{
        struct dc_softc         *sc;
        struct mii_data         *mii;
        struct ifmedia          *ifm;

        sc = ifp->if_softc;
        mii = device_get_softc(sc->dc_miibus);
        mii_pollstat(mii);
        ifm = &mii->mii_media;
        if (DC_IS_DAVICOM(sc)) {
                if (IFM_SUBTYPE(ifm->ifm_media) == IFM_HPNA_1) {
                        ifmr->ifm_active = ifm->ifm_media;
                        ifmr->ifm_status = 0;
                        return;
                }
        }
        ifmr->ifm_active = mii->mii_media_active;
        ifmr->ifm_status = mii->mii_media_status;

        return;
}

static int dc_ioctl(ifp, command, data, cr)
        struct ifnet            *ifp;
        u_long                  command;
        caddr_t                 data;
        struct ucred            *cr;
{
        struct dc_softc         *sc = ifp->if_softc;
        struct ifreq            *ifr = (struct ifreq *) data;
        struct mii_data         *mii;
        int                     s, error = 0;

        s = splimp();

        switch(command) {
        case SIOCSIFFLAGS:
                if (ifp->if_flags & IFF_UP) {
                        int need_setfilt = (ifp->if_flags ^ sc->dc_if_flags) &
                                (IFF_PROMISC | IFF_ALLMULTI);
                        if (ifp->if_flags & IFF_RUNNING) {
                                if (need_setfilt)
                                        dc_setfilt(sc);
                        } else {
                                sc->dc_txthresh = 0;
                                dc_init(sc);
                        }
                } else {
                        if (ifp->if_flags & IFF_RUNNING)
                                dc_stop(sc);
                }
                sc->dc_if_flags = ifp->if_flags;
                error = 0;
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                dc_setfilt(sc);
                error = 0;
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                mii = device_get_softc(sc->dc_miibus);
                error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
                break;
        default:
                error = ether_ioctl(ifp, command, data);
                break;
        }

        (void)splx(s);

        return(error);
}

static void dc_watchdog(ifp)
        struct ifnet            *ifp;
{
        struct dc_softc         *sc;

        sc = ifp->if_softc;

        ifp->if_oerrors++;
        if_printf(ifp, "watchdog timeout\n");

        dc_stop(sc);
        dc_reset(sc);
        dc_init(sc);

        if (!ifq_is_empty(&ifp->if_snd))
                dc_start(ifp);

        return;
}

/*
 * Stop the adapter and free any mbufs allocated to the
 * RX and TX lists.
 */
static void dc_stop(sc)
        struct dc_softc         *sc;
{
        int             i;
        struct ifnet            *ifp;

        ifp = &sc->arpcom.ac_if;
        ifp->if_timer = 0;

        callout_stop(&sc->dc_stat_timer);

        ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);

        DC_CLRBIT(sc, DC_NETCFG, (DC_NETCFG_RX_ON|DC_NETCFG_TX_ON));
        CSR_WRITE_4(sc, DC_IMR, 0x00000000);
        CSR_WRITE_4(sc, DC_TXADDR, 0x00000000);
        CSR_WRITE_4(sc, DC_RXADDR, 0x00000000);
        sc->dc_link = 0;

        /*
         * Free data in the RX lists.
         */
        for (i = 0; i < DC_RX_LIST_CNT; i++) {
                if (sc->dc_cdata.dc_rx_chain[i] != NULL) {
                        m_freem(sc->dc_cdata.dc_rx_chain[i]);
                        sc->dc_cdata.dc_rx_chain[i] = NULL;
                }
        }
        bzero((char *)&sc->dc_ldata->dc_rx_list,
                sizeof(sc->dc_ldata->dc_rx_list));

        /*
         * Free the TX list buffers.
         */
        for (i = 0; i < DC_TX_LIST_CNT; i++) {
                if (sc->dc_cdata.dc_tx_chain[i] != NULL) {
                        if ((sc->dc_ldata->dc_tx_list[i].dc_ctl &
                            DC_TXCTL_SETUP) ||
                            !(sc->dc_ldata->dc_tx_list[i].dc_ctl &
                            DC_TXCTL_LASTFRAG)) {
                                sc->dc_cdata.dc_tx_chain[i] = NULL;
                                continue;
                        }
                        m_freem(sc->dc_cdata.dc_tx_chain[i]);
                        sc->dc_cdata.dc_tx_chain[i] = NULL;
                }
        }

        bzero((char *)&sc->dc_ldata->dc_tx_list,
                sizeof(sc->dc_ldata->dc_tx_list));

        return;
}

/*
 * Stop all chip I/O so that the kernel's probe routines don't
 * get confused by errant DMAs when rebooting.
 */
static void dc_shutdown(dev)
        device_t                dev;
{
        struct dc_softc         *sc;

        sc = device_get_softc(dev);

        dc_stop(sc);

        return;
}

/*
 * Device suspend routine.  Stop the interface and save some PCI
 * settings in case the BIOS doesn't restore them properly on
 * resume.
 */
static int dc_suspend(dev)
        device_t                dev;
{
        int             i;
        int                     s;
        struct dc_softc         *sc;

        s = splimp();

        sc = device_get_softc(dev);

        dc_stop(sc);

        for (i = 0; i < 5; i++)
                sc->saved_maps[i] = pci_read_config(dev, PCIR_MAPS + i * 4, 4);
        sc->saved_biosaddr = pci_read_config(dev, PCIR_BIOS, 4);
        sc->saved_intline = pci_read_config(dev, PCIR_INTLINE, 1);
        sc->saved_cachelnsz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
        sc->saved_lattimer = pci_read_config(dev, PCIR_LATTIMER, 1);

        sc->suspended = 1;

        splx(s);
        return (0);
}

/*
 * Device resume routine.  Restore some PCI settings in case the BIOS
 * doesn't, re-enable busmastering, and restart the interface if
 * appropriate.
 */
static int dc_resume(dev)
        device_t                dev;
{
        int             i;
        int                     s;
        struct dc_softc         *sc;
        struct ifnet            *ifp;

        s = splimp();

        sc = device_get_softc(dev);
        ifp = &sc->arpcom.ac_if;

        dc_acpi(dev);

        /* better way to do this? */
        for (i = 0; i < 5; i++)
                pci_write_config(dev, PCIR_MAPS + i * 4, sc->saved_maps[i], 4);
        pci_write_config(dev, PCIR_BIOS, sc->saved_biosaddr, 4);
        pci_write_config(dev, PCIR_INTLINE, sc->saved_intline, 1);
        pci_write_config(dev, PCIR_CACHELNSZ, sc->saved_cachelnsz, 1);
        pci_write_config(dev, PCIR_LATTIMER, sc->saved_lattimer, 1);

        /* reenable busmastering */
        pci_enable_busmaster(dev);
        pci_enable_io(dev, DC_RES);

        /* reinitialize interface if necessary */
        if (ifp->if_flags & IFF_UP)
                dc_init(sc);

        sc->suspended = 0;

        splx(s);
        return (0);
}