/*- * Copyright (c) 2005 John Bicket * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer, * without modification. * 2. Redistributions in binary form must reproduce at minimum a disclaimer * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any * redistribution must be conditioned upon including a substantially * similar Disclaimer requirement for further binary redistribution. * 3. Neither the names of the above-listed copyright holders nor the names * of any contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * NO WARRANTY * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGES. * * $Id: sample.c 1525 2006-04-23 21:05:57Z dyqith $ */ /* * John Bicket's SampleRate control algorithm. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "if_athrate.h" #include "if_athvar.h" #include "ah_desc.h" #include "sample.h" #define SAMPLE_DEBUG #ifdef SAMPLE_DEBUG enum { ATH_DEBUG_RATE = 0x00000010 /* rate control */ }; #define DPRINTF(sc, _fmt, ...) do { \ if (sc->sc_debug & ATH_DEBUG_RATE) \ printf(_fmt, __VA_ARGS__); \ } while (0) #else #define DPRINTF(sc, _fmt, ...) #endif /* * This file is an implementation of the SampleRate algorithm * in "Bit-rate Selection in Wireless Networks" * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps) * * SampleRate chooses the bit-rate it predicts will provide the most * throughput based on estimates of the expected per-packet * transmission time for each bit-rate. SampleRate periodically sends * packets at bit-rates other than the current one to estimate when * another bit-rate will provide better performance. SampleRate * switches to another bit-rate when its estimated per-packet * transmission time becomes smaller than the current bit-rate's. * SampleRate reduces the number of bit-rates it must sample by * eliminating those that could not perform better than the one * currently being used. SampleRate also stops probing at a bit-rate * if it experiences several successive losses. * * The difference between the algorithm in the thesis and the one in this * file is that the one in this file uses a ewma instead of a window. * * Also, this implementation tracks the average transmission time for * a few different packet sizes independently for each link. * */ #include "svnversion.h" static char *version = "1.2 (svn " SVNVERSION ")"; static char *dev_info = "ath_rate_sample"; #define STALE_FAILURE_TIMEOUT_MS 10000 #define MIN_SWITCH_MS 1000 #define ENABLE_MRR 1 static int ath_smoothing_rate = 95; /* ewma percentage (out of 100) */ static int ath_sample_rate = 10; /* use x% of transmission time * sending at a different bit-rate */ static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *); static __inline int size_to_bin(int size) { int x = 0; for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) if (size <= packet_size_bins[x]) return x; return NUM_PACKET_SIZE_BINS - 1; } static __inline int bin_to_size(int index) { return packet_size_bins[index]; } static __inline int rate_to_ndx(struct sample_node *sn, int rate) { int x = 0; for (x = 0; x < sn->num_rates; x++) if (sn->rates[x].rate == rate) return x; return -1; } /* * Calculate the transmit duration of a frame. */ static unsigned calc_usecs_unicast_packet(struct ath_softc *sc, int length, int rix, int short_retries, int long_retries) { const HAL_RATE_TABLE *rt = sc->sc_currates; int rts, cts; unsigned t_slot = 20; unsigned t_difs = 50; unsigned t_sifs = 10; struct ieee80211com *ic = &sc->sc_ic; int tt = 0; int x = 0; int cw = WIFI_CW_MIN; int cix = rt->info[rix].controlRate; KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); if (!rt->info[rix].rateKbps) { printk(KERN_WARNING "rix %d (%d) bad ratekbps %d mode %u\n", rix, rt->info[rix].dot11Rate, rt->info[rix].rateKbps, sc->sc_curmode); return 0; } /* * XXX getting mac/phy level timings should be fixed for turbo * rates, and there is probably a way to get this from the * hal... */ switch (rt->info[rix].phy) { case IEEE80211_T_OFDM: t_slot = 9; t_sifs = 16; t_difs = 28; /* fall through */ case IEEE80211_T_TURBO: t_slot = 9; t_sifs = 8; t_difs = 28; break; case IEEE80211_T_DS: /* fall through to default */ default: /* pg 205 ieee.802.11.pdf */ t_slot = 20; t_difs = 50; t_sifs = 10; } rts = cts = 0; if ((ic->ic_flags & IEEE80211_F_USEPROT) && rt->info[rix].phy == IEEE80211_T_OFDM) { if (ic->ic_protmode == IEEE80211_PROT_RTSCTS) rts = 1; else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY) cts = 1; cix = rt->info[sc->sc_protrix].controlRate; } if (0 /*length > ic->ic_rtsthreshold */) rts = 1; if (rts || cts) { int ctsrate = rt->info[cix].rateCode; int ctsduration = 0; if (!rt->info[cix].rateKbps) { printk(KERN_WARNING "cix %d (%d) bad ratekbps %d mode %u\n", cix, rt->info[cix].dot11Rate, rt->info[cix].rateKbps, sc->sc_curmode); return 0; } ctsrate |= rt->info[cix].shortPreamble; if (rts) /* SIFS + CTS */ ctsduration += rt->info[cix].spAckDuration; ctsduration += ath_hal_computetxtime(sc->sc_ah, rt, length, rix, AH_TRUE); if (cts) /* SIFS + ACK */ ctsduration += rt->info[cix].spAckDuration; tt += (short_retries + 1) * ctsduration; } tt += t_difs; tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration); tt += (long_retries+1)*ath_hal_computetxtime(sc->sc_ah, rt, length, rix, AH_TRUE); for (x = 0; x <= short_retries + long_retries; x++) { cw = MIN(WIFI_CW_MAX, (cw + 1) * 2); tt += (t_slot * cw / 2); } return tt; } void ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) { /* NB: assumed to be zero'd by caller */ ath_rate_ctl_reset(sc, &an->an_node); } EXPORT_SYMBOL(ath_rate_node_init); void ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) { } EXPORT_SYMBOL(ath_rate_node_cleanup); void ath_rate_node_copy(struct ath_softc *sc, struct ath_node *dst, const struct ath_node *src) { struct sample_node *odst = ATH_NODE_SAMPLE(dst); const struct sample_node *osrc = (const struct sample_node *)&src[1]; memcpy(odst, osrc, sizeof(struct sample_node)); } EXPORT_SYMBOL(ath_rate_node_copy); /* * returns the ndx with the lowest average_tx_time, * or -1 if all the average_tx_times are 0. */ static __inline int best_rate_ndx(struct sample_node *sn, int size_bin, int require_acked_before) { int x = 0; int best_rate_ndx = 0; int best_rate_tt = 0; for (x = 0; x < sn->num_rates; x++) { int tt = sn->stats[size_bin][x].average_tx_time; if (tt <= 0 || (require_acked_before && !sn->stats[size_bin][x].packets_acked)) continue; /* 9 megabits never works better than 12 */ if (sn->rates[x].rate == 18) continue; /* don't use a bit-rate that has been failing */ if (sn->stats[size_bin][x].successive_failures > 3) continue; if (!best_rate_tt || best_rate_tt > tt) { best_rate_tt = tt; best_rate_ndx = x; } } return (best_rate_tt) ? best_rate_ndx : -1; } /* * pick a good "random" bit-rate to sample other than the current one */ static __inline int pick_sample_ndx(struct sample_node *sn, int size_bin) { int x = 0; int current_ndx = 0; unsigned current_tt = 0; current_ndx = sn->current_rate[size_bin]; if (current_ndx < 0) { /* no successes yet, send at the lowest bit-rate */ return 0; } current_tt = sn->stats[size_bin][current_ndx].average_tx_time; for (x = 0; x < sn->num_rates; x++) { int ndx = (sn->last_sample_ndx[size_bin]+1+x) % sn->num_rates; /* don't sample the current bit-rate */ if (ndx == current_ndx) continue; /* this bit-rate is always worse than the current one */ if (sn->stats[size_bin][ndx].perfect_tx_time > current_tt) continue; /* rarely sample bit-rates that fail a lot */ if (jiffies - sn->stats[size_bin][ndx].last_tx < ((HZ * STALE_FAILURE_TIMEOUT_MS) / 1000) && sn->stats[size_bin][ndx].successive_failures > 3) continue; /* don't sample more than 2 indexes higher * for rates higher than 11 megabits */ if (sn->rates[ndx].rate > 22 && ndx > current_ndx + 2) continue; /* 9 megabits never works better than 12 */ if (sn->rates[ndx].rate == 18) continue; /* if we're using 11 megabits, only sample up to 12 megabits */ if (sn->rates[current_ndx].rate == 22 && ndx > current_ndx + 1) continue; sn->last_sample_ndx[size_bin] = ndx; return ndx; } return current_ndx; } void ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, int shortPreamble, size_t frameLen, u_int8_t *rix, int *try0, u_int8_t *txrate) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); struct ieee80211com *ic = &sc->sc_ic; int ndx, size_bin, mrr, best_ndx, change_rates; unsigned average_tx_time; if (sn->num_rates <= 0) { printk(KERN_WARNING "%s: no rates for %s?\n", dev_info, ether_sprintf(an->an_node.ni_macaddr)); return; } mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR; size_bin = size_to_bin(frameLen); best_ndx = best_rate_ndx(sn, size_bin, !mrr); if (best_ndx >= 0) average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time; else average_tx_time = 0; if (sn->static_rate_ndx != -1) { ndx = sn->static_rate_ndx; *try0 = ATH_TXMAXTRY; } else { *try0 = mrr ? 2 : ATH_TXMAXTRY; if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin] * ssc->ath_sample_rate / 100)) { /* * we want to limit the time measuring the performance * of other bit-rates to ath_sample_rate% of the * total transmission time. */ ndx = pick_sample_ndx(sn, size_bin); if (ndx != sn->current_rate[size_bin]) sn->current_sample_ndx[size_bin] = ndx; else sn->current_sample_ndx[size_bin] = -1; sn->packets_since_sample[size_bin] = 0; } else { change_rates = 0; if (!sn->packets_sent[size_bin] || best_ndx == -1) { /* no packet has been sent successfully yet, so * pick an rssi-appropriate bit-rate. We know if * the rssi is very low that the really high * bit rates will not work. */ int initial_rate = 72; if (an->an_avgrssi > 50) { initial_rate = 108; /* 54 mbps */ } else if (an->an_avgrssi > 30) { initial_rate = 72; /* 36 mbps */ } else { initial_rate = 22; /* 11 mbps */ } for (ndx = sn->num_rates-1; ndx > 0; ndx--) { /* * pick the highest rate <= initial_rate/2 Mbps * that hasn't failed. */ if (sn->rates[ndx].rate <= initial_rate && sn->stats[size_bin][ndx].successive_failures == 0) break; } change_rates = 1; best_ndx = ndx; } else if (sn->packets_sent[size_bin] < 20) { /* let the bit-rate switch quickly during the first few packets */ change_rates = 1; } else if (jiffies - ((HZ * MIN_SWITCH_MS) / 1000) > sn->jiffies_since_switch[size_bin]) { /* 2 seconds have gone by */ change_rates = 1; } else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) { /* the current bit-rate is twice as slow as the best one */ change_rates = 1; } sn->packets_since_sample[size_bin]++; if (change_rates) { if (best_ndx != sn->current_rate[size_bin]) { DPRINTF(sc, "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d\n", dev_info, ether_sprintf(an->an_node.ni_macaddr), packet_size_bins[size_bin], sn->rates[sn->current_rate[size_bin]].rate, sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time, sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time, sn->rates[best_ndx].rate, sn->stats[size_bin][best_ndx].average_tx_time, sn->stats[size_bin][best_ndx].perfect_tx_time, sn->packets_since_switch[size_bin], mrr); } sn->packets_since_switch[size_bin] = 0; sn->current_rate[size_bin] = best_ndx; sn->jiffies_since_switch[size_bin] = jiffies; } ndx = sn->current_rate[size_bin]; sn->packets_since_switch[size_bin]++; if (size_bin == 0) { /* * set the visible txrate for this node * to the rate of small packets */ an->an_node.ni_txrate = ndx; } } } KASSERT(ndx >= 0 && ndx < sn->num_rates, ("%s: bad ndx (%d/%d) for %s?\n", dev_info, ndx, sn->num_rates, ether_sprintf(an->an_node.ni_macaddr))); *rix = sn->rates[ndx].rix; if (shortPreamble) *txrate = sn->rates[ndx].shortPreambleRateCode; else *txrate = sn->rates[ndx].rateCode; sn->packets_sent[size_bin]++; } EXPORT_SYMBOL(ath_rate_findrate); void ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, struct ath_desc *ds, int shortPreamble, size_t frame_size, u_int8_t rix) { struct sample_node *sn = ATH_NODE_SAMPLE(an); int rateCode = -1; int size_bin = 0; int ndx = 0; size_bin = size_to_bin(frame_size); ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */ if (!sn->stats[size_bin][ndx].packets_acked) ndx = 0; /* use the lowest bit-rate */ if (shortPreamble) rateCode = sn->rates[ndx].shortPreambleRateCode; else rateCode = sn->rates[ndx].rateCode; ath_hal_setupxtxdesc(sc->sc_ah, ds , rateCode, 3 /* series 1 */ , sn->rates[0].rateCode, 3 /* series 2 */ , 0, 0 /* series 3 */ ); } EXPORT_SYMBOL(ath_rate_setupxtxdesc); static void update_stats(struct ath_softc *sc, struct ath_node *an, int frame_size, int ndx0, int tries0, int ndx1, int tries1, int ndx2, int tries2, int ndx3, int tries3, int short_tries, int tries, int status) { const HAL_RATE_TABLE *rt = sc->sc_currates; struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); int tt = 0; int tries_so_far = 0; int size_bin = 0; int size = 0; int rate = 0; size_bin = size_to_bin(frame_size); size = bin_to_size(size_bin); rate = sn->rates[ndx0].rate; if (!rt->info[ndx0].rateKbps) { /* * sometimes we get feedback back for packets we didn't send. * just ignore these packets. */ return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix, short_tries-1, MIN(tries0, tries) - 1); tries_so_far += tries0; if (tries1 && tries0 < tries) { tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix, short_tries - 1, MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries1; if (tries2 && tries0 + tries1 < tries) { tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix, short_tries - 1, MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries2; if (tries3 && tries0 + tries1 + tries2 < tries) { tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix, short_tries - 1, MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); } if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) { /* just average the first few packets */ int avg_tx = sn->stats[size_bin][ndx0].average_tx_time; int packets = sn->stats[size_bin][ndx0].total_packets; sn->stats[size_bin][ndx0].average_tx_time = (tt + (avg_tx * packets)) / (packets + 1); } else { /* use a ewma */ sn->stats[size_bin][ndx0].average_tx_time = ((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) + (tt * (100 - ssc->ath_smoothing_rate))) / 100; } if (status) { int y; sn->stats[size_bin][ndx0].successive_failures++; for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) { /* also say larger packets failed since we * assume if a small packet fails at a lower * bit-rate then a larger one will also. */ sn->stats[y][ndx0].successive_failures++; sn->stats[y][ndx0].last_tx = jiffies; sn->stats[y][ndx0].tries += tries; sn->stats[y][ndx0].total_packets++; } } else { sn->stats[size_bin][ndx0].packets_acked++; sn->stats[size_bin][ndx0].successive_failures = 0; } sn->stats[size_bin][ndx0].tries += tries; sn->stats[size_bin][ndx0].last_tx = jiffies; sn->stats[size_bin][ndx0].total_packets++; if (ndx0 == sn->current_sample_ndx[size_bin]) { DPRINTF(sc, "%s: %s size %d sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d) status %d\n", dev_info, ether_sprintf(an->an_node.ni_macaddr), size, rate, short_tries, tries, tt, sn->stats[size_bin][ndx0].average_tx_time, sn->stats[size_bin][ndx0].perfect_tx_time, status); sn->sample_tt[size_bin] = tt; sn->current_sample_ndx[size_bin] = -1; } } void ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, const struct ath_desc *ds) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct ieee80211com *ic = &sc->sc_ic; const struct ar5212_desc *ads = (const struct ar5212_desc *)&ds->ds_ctl0; int final_rate = 0; int short_tries = 0; int long_tries = 0; int ndx = -1; int frame_size = 0; int mrr; final_rate = sc->sc_hwmap[ds->ds_txstat.ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate; short_tries = ds->ds_txstat.ts_shortretry + 1; long_tries = ds->ds_txstat.ts_longretry + 1; frame_size = ds->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */ if (frame_size == 0) frame_size = 1500; if (sn->num_rates <= 0) { DPRINTF(sc, "%s: %s %s no rates yet\n", dev_info, ether_sprintf(an->an_node.ni_macaddr), __func__); return; } mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR; if (sc->sc_mrretry && ds->ds_txstat.ts_status) { /* this packet failed */ DPRINTF(sc, "%s: %s size %d rate/try %d/%d %d/%d %d/%d %d/%d status %s retries (%d/%d)\n", dev_info, ether_sprintf(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), sc->sc_hwmap[ads->xmit_rate0].ieeerate, ads->xmit_tries0, sc->sc_hwmap[ads->xmit_rate1].ieeerate, ads->xmit_tries1, sc->sc_hwmap[ads->xmit_rate2].ieeerate, ads->xmit_tries2, sc->sc_hwmap[ads->xmit_rate3].ieeerate, ads->xmit_tries3, ds->ds_txstat.ts_status ? "FAIL" : "OK", short_tries, long_tries); } if (!mrr || !(ds->ds_txstat.ts_rate & HAL_TXSTAT_ALTRATE)) { /* only one rate was used */ ndx = rate_to_ndx(sn, final_rate); if (ndx >= 0 && ndx < sn->num_rates) { update_stats(sc, an, frame_size, ndx, long_tries, 0, 0, 0, 0, 0, 0, short_tries, long_tries, ds->ds_txstat.ts_status); } } else { int rate0, tries0, ndx0; int rate1, tries1, ndx1; int rate2, tries2, ndx2; int rate3, tries3, ndx3; int finalTSIdx = ads->final_ts_index; /* * Process intermediate rates that failed. */ rate0 = sc->sc_hwmap[ads->xmit_rate0].ieeerate; tries0 = ads->xmit_tries0; ndx0 = rate_to_ndx(sn, rate0); rate1 = sc->sc_hwmap[ads->xmit_rate1].ieeerate; tries1 = ads->xmit_tries1; ndx1 = rate_to_ndx(sn, rate1); rate2 = sc->sc_hwmap[ads->xmit_rate2].ieeerate; tries2 = ads->xmit_tries2; ndx2 = rate_to_ndx(sn, rate2); rate3 = sc->sc_hwmap[ads->xmit_rate3].ieeerate; tries3 = ads->xmit_tries3; ndx3 = rate_to_ndx(sn, rate3); #if 0 DPRINTF(sc, "%s: %s size %d finaltsidx %d tries %d status %d rate/try %d/%d %d/%d %d/%d %d/%d\n", dev_info, ether_sprintf(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), finalTSIdx, long_tries, ds->ds_txstat.ts_status, rate0, tries0, rate1, tries1, rate2, tries2, rate3, tries3); #endif if (tries0) update_stats(sc, an, frame_size, ndx0, tries0, ndx1, tries1, ndx2, tries2, ndx3, tries3, short_tries, ds->ds_txstat.ts_longretry + 1, long_tries > tries0); if (tries1 && finalTSIdx > 0) update_stats(sc, an, frame_size, ndx1, tries1, ndx2, tries2, ndx3, tries3, 0, 0, short_tries, ds->ds_txstat.ts_longretry + 1 - tries0, ds->ds_txstat.ts_status); if (tries2 && finalTSIdx > 1) update_stats(sc, an, frame_size, ndx2, tries2, ndx3, tries3, 0, 0, 0, 0, short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1, ds->ds_txstat.ts_status); if (tries3 && finalTSIdx > 2) update_stats(sc, an, frame_size, ndx3, tries3, 0, 0, 0, 0, 0, 0, short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1 - tries2, ds->ds_txstat.ts_status); } } EXPORT_SYMBOL(ath_rate_tx_complete); void ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) { DPRINTF(sc, "%s: %s %s\n", dev_info, ether_sprintf(an->an_node.ni_macaddr), __func__); if (isnew) ath_rate_ctl_reset(sc, &an->an_node); } EXPORT_SYMBOL(ath_rate_newassoc); /* * Initialize the tables for a node. */ static void ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni) { struct ath_node *an = ATH_NODE(ni); struct sample_node *sn = ATH_NODE_SAMPLE(an); struct ieee80211vap *vap = ni->ni_vap; const HAL_RATE_TABLE *rt = sc->sc_currates; int x, y; int srate; sn->num_rates = 0; if (rt == NULL) { printk(KERN_WARNING "no rates yet! mode %u\n", sc->sc_curmode); return; } sn->static_rate_ndx = -1; sn->num_rates = ni->ni_rates.rs_nrates; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL; sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate]; if (sn->rates[x].rix == 0xff) { DPRINTF(sc, "%s: %s ignore bogus rix at %d\n", dev_info, __func__, x); continue; } sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode; sn->rates[x].shortPreambleRateCode = rt->info[sn->rates[x].rix].rateCode | rt->info[sn->rates[x].rix].shortPreamble; } ni->ni_txrate = 0; sn->num_rates = ni->ni_rates.rs_nrates; if (sn->num_rates <= 0) { DPRINTF(sc, "%s: %s %s no rates (fixed %d) \n", dev_info, __func__, ether_sprintf(ni->ni_macaddr), vap->iv_fixed_rate); /* there are no rates yet we're done */ return; } if (vap->iv_fixed_rate != -1) { srate = sn->num_rates - 1; /* * A fixed rate is to be used; ic_fixed_rate is an * index into the supported rate set. Convert this * to the index into the negotiated rate set for * the node. We know the rate is there because the * rate set is checked when the station associates. */ /* NB: the rate set is assumed sorted */ for (; srate >= 0 && (ni->ni_rates.rs_rates[srate] & IEEE80211_RATE_VAL) != vap->iv_fixed_rate; srate--); KASSERT(srate >= 0, ("fixed rate %d not in rate set", vap->iv_fixed_rate)); sn->static_rate_ndx = srate; ni->ni_txrate = srate; DPRINTF(sc, "%s: %s %s fixed rate %d%sMbps\n", dev_info, __func__, ether_sprintf(ni->ni_macaddr), sn->rates[srate].rate / 2, (sn->rates[srate].rate % 0x1) ? ".5" : " "); return; } for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) { int size = bin_to_size(y); int ndx = 0; sn->packets_sent[y] = 0; sn->current_sample_ndx[y] = -1; sn->last_sample_ndx[y] = 0; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { sn->stats[y][x].successive_failures = 0; sn->stats[y][x].tries = 0; sn->stats[y][x].total_packets = 0; sn->stats[y][x].packets_acked = 0; sn->stats[y][x].last_tx = 0; sn->stats[y][x].perfect_tx_time = calc_usecs_unicast_packet(sc, size, sn->rates[x].rix, 0, 0); sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time; } /* set the initial rate */ for (ndx = sn->num_rates-1; ndx > 0; ndx--) if (sn->rates[ndx].rate <= 72) break; sn->current_rate[y] = ndx; } DPRINTF(sc, "%s: %s %s %d rates %d%sMbps (%dus)- %d%sMbps (%dus)\n", dev_info, __func__, ether_sprintf(ni->ni_macaddr), sn->num_rates, sn->rates[0].rate / 2, sn->rates[0].rate % 0x1 ? ".5" : "", sn->stats[1][0].perfect_tx_time, sn->rates[sn->num_rates-1].rate / 2, sn->rates[sn->num_rates-1].rate % 0x1 ? ".5" : "", sn->stats[1][sn->num_rates-1].perfect_tx_time); ni->ni_txrate = sn->current_rate[0]; } static void ath_rate_cb(void *arg, struct ieee80211_node *ni) { ath_rate_ctl_reset(ni->ni_ic->ic_dev->priv, ni); } /* * Reset the rate control state for each 802.11 state transition. */ void ath_rate_newstate(struct ieee80211vap *vap, enum ieee80211_state newstate) { struct ieee80211com *ic = vap->iv_ic; if (newstate == IEEE80211_S_RUN) { if (ic->ic_opmode != IEEE80211_M_STA) { /* * Sync rates for associated stations and neighbors. */ ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, NULL); } ath_rate_newassoc(ic->ic_dev->priv, ATH_NODE(vap->iv_bss), 1); } } EXPORT_SYMBOL(ath_rate_newstate); struct ath_ratectrl * ath_rate_attach(struct ath_softc *sc) { struct sample_softc *osc; DPRINTF(sc, "%s: %s\n", dev_info, __func__); osc = kmalloc(sizeof(struct sample_softc), GFP_ATOMIC); if (osc == NULL) return NULL; osc->arc.arc_space = sizeof(struct sample_node); osc->arc.arc_vap_space = 0; osc->ath_smoothing_rate = ath_smoothing_rate; osc->ath_sample_rate = ath_sample_rate; return &osc->arc; } EXPORT_SYMBOL(ath_rate_attach); void ath_rate_detach(struct ath_ratectrl *arc) { struct sample_softc *osc = (struct sample_softc *) arc; kfree(osc); } EXPORT_SYMBOL(ath_rate_detach); MODULE_AUTHOR("John Bicket"); MODULE_DESCRIPTION("SampleRate bit-rate selection algorithm for Atheros devices"); #ifdef MODULE_VERSION MODULE_VERSION("svn "SVNVERSION); #endif #ifdef MODULE_LICENSE MODULE_LICENSE("Dual BSD/GPL"); #endif static int __init init_ath_rate_sample(void) { printk(KERN_INFO "%s: %s\n", dev_info, version); return (0); } module_init(init_ath_rate_sample); static void __exit exit_ath_rate_sample(void) { printk(KERN_INFO "%s: unloaded\n", dev_info); } module_exit(exit_ath_rate_sample);