void
ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
int shortPreamble, size_t frameLen,
u_int8_t *rix0, int *try0, u_int8_t *txrate)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
#define RATE(ix) (DOT11RATE(ix) / 2)
struct sample_node *sn = ATH_NODE_SAMPLE(an);
struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
struct ifnet *ifp = sc->sc_ifp;
struct ieee80211com *ic = ifp->if_l2com;
const HAL_RATE_TABLE *rt = sc->sc_currates;
const int size_bin = size_to_bin(frameLen);
int rix, mrr, best_rix, change_rates;
unsigned average_tx_time;
ath_rate_update_static_rix(sc, &an->an_node);
if (sn->static_rix != -1) {
rix = sn->static_rix;
*try0 = ATH_TXMAXTRY;
goto done;
}
/* XXX TODO: this doesn't know about 11gn vs 11g protection; teach it */
mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
best_rix = pick_best_rate(an, rt, size_bin, !mrr);
if (best_rix >= 0) {
average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
} else {
average_tx_time = 0;
}
/*
* Limit the time measuring the performance of other tx
* rates to sample_rate% of the total transmission time.
*/
if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
rix = pick_sample_rate(ssc, an, rt, size_bin);
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
average_tx_time,
sn->sample_tt[size_bin],
bin_to_size(size_bin),
dot11rate(rt, rix),
dot11rate_label(rt, rix),
dot11rate(rt, sn->current_rix[size_bin]),
dot11rate_label(rt, sn->current_rix[size_bin]));
if (rix != sn->current_rix[size_bin]) {
sn->current_sample_rix[size_bin] = rix;
} else {
sn->current_sample_rix[size_bin] = -1;
}
sn->packets_since_sample[size_bin] = 0;
} else {
change_rates = 0;
if (!sn->packets_sent[size_bin] || best_rix == -1) {
/* no packet has been sent successfully yet */
change_rates = 1;
if (an->an_node.ni_flags & IEEE80211_NODE_HT)
best_rix =
ath_rate_pick_seed_rate_ht(sc, an, frameLen);
else
best_rix =
ath_rate_pick_seed_rate_legacy(sc, an, frameLen);
} else if (sn->packets_sent[size_bin] < 20) {
/* let the bit-rate switch quickly during the first few packets */
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: switching quickly..", __func__);
change_rates = 1;
} else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
/* min_switch seconds have gone by */
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: min_switch %d > ticks_since_switch %d..",
__func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]);
change_rates = 1;
} else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) &&
(2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) {
/* the current bit-rate is twice as slow as the best one */
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: 2x att (= %d) < cur_rix att %d",
__func__,
2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time);
change_rates = 1;
} else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) {
int cur_rix = sn->current_rix[size_bin];
int cur_att = sn->stats[size_bin][cur_rix].average_tx_time;
/*
* If the node is HT, upgrade it if the MCS rate is
* higher and the average tx time is within 20% of
* the current rate. It can fail a little.
*
* This is likely not optimal!
*/
#if 0
printf("cur rix/att %x/%d, best rix/att %x/%d\n",
MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time);
#endif
if ((MCS(best_rix) > MCS(cur_rix)) &&
(average_tx_time * 8) <= (cur_att * 10)) {
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d",
__func__,
MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att);
change_rates = 1;
}
}
sn->packets_since_sample[size_bin]++;
if (change_rates) {
if (best_rix != sn->current_rix[size_bin]) {
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL,
&an->an_node,
"%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
__func__,
bin_to_size(size_bin),
RATE(sn->current_rix[size_bin]),
sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
RATE(best_rix),
sn->stats[size_bin][best_rix].average_tx_time,
sn->stats[size_bin][best_rix].perfect_tx_time,
sn->packets_since_switch[size_bin],
mrr);
}
sn->packets_since_switch[size_bin] = 0;
sn->current_rix[size_bin] = best_rix;
sn->ticks_since_switch[size_bin] = ticks;
/*
* Set the visible txrate for this node.
*/
an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
}
rix = sn->current_rix[size_bin];
sn->packets_since_switch[size_bin]++;
}
*try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
done:
KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
*rix0 = rix;
*txrate = rt->info[rix].rateCode
| (shortPreamble ? rt->info[rix].shortPreamble : 0);
sn->packets_sent[size_bin]++;
#undef DOT11RATE
#undef MCS
#undef RATE
}
void
ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
int shortPreamble, size_t frameLen,
u_int8_t *rix0, int *try0, u_int8_t *txrate)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define RATE(ix) (DOT11RATE(ix) / 2)
struct sample_node *sn = ATH_NODE_SAMPLE(an);
struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
struct ifnet *ifp = sc->sc_ifp;
struct ieee80211com *ic = ifp->if_l2com;
const HAL_RATE_TABLE *rt = sc->sc_currates;
const int size_bin = size_to_bin(frameLen);
int rix, mrr, best_rix, change_rates;
unsigned average_tx_time;
if (sn->static_rix != -1) {
rix = sn->static_rix;
*try0 = ATH_TXMAXTRY;
goto done;
}
mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
best_rix = pick_best_rate(sn, rt, size_bin, !mrr);
if (best_rix >= 0) {
average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
} else {
average_tx_time = 0;
}
/*
* Limit the time measuring the performance of other tx
* rates to sample_rate% of the total transmission time.
*/
if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
rix = pick_sample_rate(ssc, sn, rt, size_bin);
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node, "size %u sample rate %d current rate %d",
bin_to_size(size_bin), RATE(rix),
RATE(sn->current_rix[size_bin]));
if (rix != sn->current_rix[size_bin]) {
sn->current_sample_rix[size_bin] = rix;
} else {
sn->current_sample_rix[size_bin] = -1;
}
sn->packets_since_sample[size_bin] = 0;
} else {
change_rates = 0;
if (!sn->packets_sent[size_bin] || best_rix == -1) {
/* no packet has been sent successfully yet */
for (rix = rt->rateCount-1; rix > 0; rix--) {
if ((sn->ratemask & (1<<rix)) == 0)
continue;
/*
* Pick the highest rate <= 36 Mbps
* that hasn't failed.
*/
if (DOT11RATE(rix) <= 72 &&
sn->stats[size_bin][rix].successive_failures == 0) {
break;
}
}
change_rates = 1;
best_rix = rix;
} else if (sn->packets_sent[size_bin] < 20) {
/* let the bit-rate switch quickly during the first few packets */
change_rates = 1;
} else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
/* min_switch seconds have gone by */
change_rates = 1;
} else if (2*average_tx_time < sn->stats[size_bin][sn->current_rix[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_rix != sn->current_rix[size_bin]) {
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL,
&an->an_node,
"%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
__func__,
bin_to_size(size_bin),
RATE(sn->current_rix[size_bin]),
sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
RATE(best_rix),
sn->stats[size_bin][best_rix].average_tx_time,
sn->stats[size_bin][best_rix].perfect_tx_time,
sn->packets_since_switch[size_bin],
mrr);
}
sn->packets_since_switch[size_bin] = 0;
sn->current_rix[size_bin] = best_rix;
sn->ticks_since_switch[size_bin] = ticks;
/*
* Set the visible txrate for this node.
*/
an->an_node.ni_txrate = DOT11RATE(best_rix);
}
rix = sn->current_rix[size_bin];
sn->packets_since_switch[size_bin]++;
}
*try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
done:
KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
*rix0 = rix;
*txrate = rt->info[rix].rateCode
| (shortPreamble ? rt->info[rix].shortPreamble : 0);
sn->packets_sent[size_bin]++;
#undef DOT11RATE
#undef RATE
}
