2 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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17 * from this software without specific prior written permission.
19 * Alternatively, this software may be distributed under the terms of the
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36 * $FreeBSD: src/sys/dev/ath/ath_rate/onoe/onoe.c,v 1.8.2.3 2006/02/24 19:51:11 sam Exp $
37 * $DragonFly: src/sys/dev/netif/ath/rate_onoe/onoe.c,v 1.2 2006/09/05 00:55:39 dillon Exp $
41 * Atsushi Onoe's rate control algorithm.
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysctl.h>
47 #include <sys/module.h>
48 #include <sys/kernel.h>
50 #include <sys/errno.h>
51 #include <sys/serialize.h>
53 #include <machine/bus.h>
54 #include <machine/resource.h>
57 #include <sys/socket.h>
60 #include <net/if_media.h>
61 #include <net/if_arp.h>
62 #include <net/ethernet.h> /* XXX for ether_sprintf */
64 #include <netproto/802_11/ieee80211_var.h>
68 #include <dev/netif/ath/ath/if_athvar.h>
69 #include <dev/netif/ath/rate_onoe/onoe.h>
70 #include <contrib/dev/ath/ah_desc.h>
75 ATH_DEBUG_RATE = 0x00000010, /* rate control */
77 #define DPRINTF(sc, _fmt, ...) do { \
78 if (sc->sc_debug & ATH_DEBUG_RATE) \
79 printf(_fmt, __VA_ARGS__); \
82 #define DPRINTF(sc, _fmt, ...)
86 * Default parameters for the rate control algorithm. These are
87 * all tunable with sysctls. The rate controller runs periodically
88 * (each ath_rateinterval ms) analyzing transmit statistics for each
89 * neighbor/station (when operating in station mode this is only the AP).
90 * If transmits look to be working well over a sampling period then
91 * it gives a "raise rate credit". If transmits look to not be working
92 * well than it deducts a credit. If the credits cross a threshold then
93 * the transmit rate is raised. Various error conditions force the
94 * the transmit rate to be dropped.
96 * The decision to issue/deduct a credit is based on the errors and
97 * retries accumulated over the sampling period. ath_rate_raise defines
98 * the percent of retransmits for which a credit is issued/deducted.
99 * ath_rate_raise_threshold defines the threshold on credits at which
100 * the transmit rate is increased.
102 * XXX this algorithm is flawed.
104 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */
105 static int ath_rate_raise = 10; /* add credit threshold */
106 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */
108 static void ath_ratectl(void *);
109 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *,
111 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *);
112 static void ath_rate_ctl(void *, struct ieee80211_node *);
115 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
117 /* NB: assumed to be zero'd by caller */
118 ath_rate_update(sc, &an->an_node, 0);
122 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
127 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
128 int shortPreamble, size_t frameLen,
129 uint8_t *rix, int *try0, uint8_t *txrate)
131 struct onoe_node *on = ATH_NODE_ONOE(an);
133 *rix = on->on_tx_rix0;
134 *try0 = on->on_tx_try0;
136 *txrate = on->on_tx_rate0sp;
138 *txrate = on->on_tx_rate0;
142 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
143 struct ath_desc *ds, int shortPreamble, uint8_t rix)
145 struct onoe_node *on = ATH_NODE_ONOE(an);
147 ath_hal_setupxtxdesc(sc->sc_ah, ds
148 , on->on_tx_rate1sp, 2 /* series 1 */
149 , on->on_tx_rate2sp, 2 /* series 2 */
150 , on->on_tx_rate3sp, 2 /* series 3 */
155 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
156 const struct ath_desc *ds, const struct ath_desc *ds0)
158 struct onoe_node *on = ATH_NODE_ONOE(an);
160 if (ds->ds_txstat.ts_status == 0)
164 on->on_tx_retr += ds->ds_txstat.ts_shortretry
165 + ds->ds_txstat.ts_longretry;
169 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
172 ath_rate_ctl_start(sc, &an->an_node);
176 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)
178 struct ath_node *an = ATH_NODE(ni);
179 struct onoe_node *on = ATH_NODE_ONOE(an);
180 const HAL_RATE_TABLE *rt = sc->sc_currates;
183 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
185 DPRINTF(sc, "%s: set xmit rate for %6D to %dM\n",
186 __func__, ni->ni_macaddr, ":",
187 ni->ni_rates.rs_nrates > 0 ?
188 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);
190 ni->ni_txrate = rate;
192 * Before associating a node has no rate set setup
193 * so we can't calculate any transmit codes to use.
194 * This is ok since we should never be sending anything
195 * but management frames and those always go at the
196 * lowest hardware rate.
198 if (ni->ni_rates.rs_nrates == 0)
200 on->on_tx_rix0 = sc->sc_rixmap[
201 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL];
202 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode;
204 on->on_tx_rate0sp = on->on_tx_rate0 |
205 rt->info[on->on_tx_rix0].shortPreamble;
206 if (sc->sc_mrretry) {
208 * Hardware supports multi-rate retry; setup two
209 * step-down retry rates and make the lowest rate
210 * be the ``last chance''. We use 4, 2, 2, 2 tries
211 * respectively (4 is set here, the rest are fixed
212 * in the xmit routine).
214 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */
217 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
218 on->on_tx_rate1 = rt->info[rix].rateCode;
219 on->on_tx_rate1sp = on->on_tx_rate1 |
220 rt->info[rix].shortPreamble;
222 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
226 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];
227 on->on_tx_rate2 = rt->info[rix].rateCode;
228 on->on_tx_rate2sp = on->on_tx_rate2 |
229 rt->info[rix].shortPreamble;
231 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
234 /* NB: only do this if we didn't already do it above */
235 on->on_tx_rate3 = rt->info[0].rateCode;
237 on->on_tx_rate3 | rt->info[0].shortPreamble;
239 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
242 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */
243 on->on_tx_rate1 = on->on_tx_rate1sp = 0;
244 on->on_tx_rate2 = on->on_tx_rate2sp = 0;
245 on->on_tx_rate3 = on->on_tx_rate3sp = 0;
248 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0;
252 * Set the starting transmit rate for a node.
255 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni)
257 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
258 struct ieee80211com *ic = &sc->sc_ic;
261 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates"));
262 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
264 * No fixed rate is requested. For 11b start with
265 * the highest negotiated rate; otherwise, for 11g
266 * and 11a, we start "in the middle" at 24Mb or 36Mb.
268 srate = ni->ni_rates.rs_nrates - 1;
269 if (sc->sc_curmode != IEEE80211_MODE_11B) {
271 * Scan the negotiated rate set to find the
274 /* NB: the rate set is assumed sorted */
275 for (; srate >= 0 && RATE(srate) > 72; srate--)
277 KASSERT(srate >= 0, ("bogus rate set"));
281 * A fixed rate is to be used; ic_fixed_rate is an
282 * index into the supported rate set. Convert this
283 * to the index into the negotiated rate set for
284 * the node. We know the rate is there because the
285 * rate set is checked when the station associates.
287 const struct ieee80211_rateset *rs =
288 &ic->ic_sup_rates[ic->ic_curmode];
289 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
290 /* NB: the rate set is assumed sorted */
291 srate = ni->ni_rates.rs_nrates - 1;
292 for (; srate >= 0 && RATE(srate) != r; srate--)
295 ("fixed rate %d not in rate set", ic->ic_fixed_rate));
297 ath_rate_update(sc, ni, srate);
302 ath_rate_cb(void *arg, struct ieee80211_node *ni)
304 struct ath_softc *sc = arg;
306 ath_rate_update(sc, ni, 0);
310 * Reset the rate control state for each 802.11 state transition.
313 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
315 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
316 struct ieee80211com *ic = &sc->sc_ic;
317 struct ifnet *ifp = &ic->ic_if;
318 struct ieee80211_node *ni;
320 ASSERT_SERIALIZED(ifp->if_serializer);
322 if (state == IEEE80211_S_INIT) {
323 callout_stop(&osc->timer);
326 if (ic->ic_opmode == IEEE80211_M_STA) {
328 * Reset local xmit state; this is really only
329 * meaningful when operating in station mode.
332 if (state == IEEE80211_S_RUN) {
333 ath_rate_ctl_start(sc, ni);
335 ath_rate_update(sc, ni, 0);
339 * When operating as a station the node table holds
340 * the AP's that were discovered during scanning.
341 * For any other operating mode we want to reset the
342 * tx rate state of each node.
344 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc);
345 ath_rate_update(sc, ic->ic_bss, 0);
347 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE &&
348 state == IEEE80211_S_RUN) {
351 * Start the background rate control thread if we
352 * are not configured to use a fixed xmit rate.
354 interval = ath_rateinterval;
355 if (ic->ic_opmode == IEEE80211_M_STA)
357 callout_reset(&osc->timer, (interval * hz) / 1000,
363 * Examine and potentially adjust the transmit rate.
366 ath_rate_ctl(void *arg, struct ieee80211_node *ni)
368 struct ath_softc *sc = arg;
369 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni));
370 struct ieee80211_rateset *rs = &ni->ni_rates;
371 int dir = 0, nrate, enough;
375 * XXX: very primitive version.
377 enough = (on->on_tx_ok + on->on_tx_err >= 10);
379 /* no packet reached -> down */
380 if (on->on_tx_err > 0 && on->on_tx_ok == 0)
383 /* all packets needs retry in average -> down */
384 if (enough && on->on_tx_ok < on->on_tx_retr)
387 /* no error and less than rate_raise% of packets need retry -> up */
388 if (enough && on->on_tx_err == 0 &&
389 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100)
392 DPRINTF(sc, "%6D: ok %d err %d retr %d upper %d dir %d\n",
394 on->on_tx_ok, on->on_tx_err, on->on_tx_retr,
395 on->on_tx_upper, dir);
397 nrate = ni->ni_txrate;
400 if (enough && on->on_tx_upper > 0)
406 sc->sc_stats.ast_rate_drop++;
411 /* raise rate if we hit rate_raise_threshold */
412 if (++on->on_tx_upper < ath_rate_raise_threshold)
415 if (nrate + 1 < rs->rs_nrates) {
417 sc->sc_stats.ast_rate_raise++;
422 if (nrate != ni->ni_txrate) {
423 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n",
425 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2,
426 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2,
427 on->on_tx_ok, on->on_tx_err, on->on_tx_retr);
428 ath_rate_update(sc, ni, nrate);
430 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0;
435 ath_ratectl(void *arg)
437 struct ifnet *ifp = arg;
438 struct ath_softc *sc = ifp->if_softc;
439 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc;
440 struct ieee80211com *ic = &sc->sc_ic;
443 lwkt_serialize_enter(ifp->if_serializer);
445 if (ifp->if_flags & IFF_RUNNING) {
446 sc->sc_stats.ast_rate_calls++;
448 if (ic->ic_opmode == IEEE80211_M_STA)
449 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */
451 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc);
453 interval = ath_rateinterval;
454 if (ic->ic_opmode == IEEE80211_M_STA)
456 callout_reset(&osc->timer, (interval * hz) / 1000, ath_ratectl, ifp);
458 lwkt_serialize_exit(ifp->if_serializer);
462 ath_rate_sysctlattach(struct ath_softc *sc)
464 struct sysctl_ctx_list *ctx = &sc->sc_sysctl_ctx;
465 struct sysctl_oid *tree = sc->sc_sysctl_tree;
467 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
468 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0,
469 "rate control: operation interval (ms)");
470 /* XXX bounds check values */
471 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
472 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0,
473 "rate control: retry threshold to credit rate raise (%%)");
474 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
475 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0,
476 "rate control: # good periods before raising rate");
479 struct ath_ratectrl *
480 ath_rate_attach(struct ath_softc *sc)
482 struct onoe_softc *osc;
484 osc = kmalloc(sizeof(struct onoe_softc), M_DEVBUF, M_WAITOK | M_ZERO);
485 osc->arc.arc_space = sizeof(struct onoe_node);
486 callout_init(&osc->timer);
487 ath_rate_sysctlattach(sc);
492 ath_rate_detach(struct ath_ratectrl *arc)
494 struct onoe_softc *osc = (struct onoe_softc *) arc;
496 kfree(osc, M_DEVBUF);
500 ath_rate_stop(struct ath_ratectrl *arc)
502 struct onoe_softc *osc = (struct onoe_softc *) arc;
504 /* ASSERT_SERIALIZED */
505 callout_stop(&osc->timer);
512 onoe_modevent(module_t mod, int type, void *unused)
517 printf("ath_rate: <Atsushi Onoe's rate control algorithm>\n");
525 static moduledata_t onoe_mod = {
530 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
531 MODULE_VERSION(ath_rate, 1);
532 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1);