/*
* Pick a non-HT rate to begin using.
*/
static int
ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an,
int frameLen)
{
#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)
int rix = -1;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const int size_bin = size_to_bin(frameLen);
/* no packet has been sent successfully yet */
for (rix = rt->rateCount-1; rix > 0; rix--) {
if ((sn->ratemask & (1<<rix)) == 0)
continue;
/* Skip HT rates */
if (rt->info[rix].phy == IEEE80211_T_HT)
continue;
/*
* Pick the highest rate <= 36 Mbps
* that hasn't failed.
*/
if (DOT11RATE(rix) <= 72 &&
sn->stats[size_bin][rix].successive_failures == 0) {
break;
}
}
return rix;
#undef RATE
#undef MCS
#undef DOT11RATE
}
/*
* Pick a good "random" bit-rate to sample other than the current one.
*/
static __inline int
pick_sample_rate(struct sample_softc *ssc , struct sample_node *sn,
const HAL_RATE_TABLE *rt, int size_bin)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
int current_rix, rix;
unsigned current_tt;
uint32_t mask;
current_rix = sn->current_rix[size_bin];
if (current_rix < 0) {
/* no successes yet, send at the lowest bit-rate */
return 0;
}
current_tt = sn->stats[size_bin][current_rix].average_tx_time;
rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
mask = sn->ratemask &~ (1<<current_rix);/* don't sample current rate */
while (mask != 0) {
if ((mask & (1<<rix)) == 0) { /* not a supported rate */
nextrate:
if (++rix >= rt->rateCount)
rix = 0;
continue;
}
/* this bit-rate is always worse than the current one */
if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
mask &= ~(1<<rix);
goto nextrate;
}
/* rarely sample bit-rates that fail a lot */
if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
mask &= ~(1<<rix);
goto nextrate;
}
/* don't sample more than 2 rates higher for rates > 11M */
if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
mask &= ~(1<<rix);
goto nextrate;
}
sn->last_sample_rix[size_bin] = rix;
return rix;
}
return current_rix;
#undef DOT11RATE
}
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
}
/*
* Pick a good "random" bit-rate to sample other than the current one.
*/
static __inline int
pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
const HAL_RATE_TABLE *rt, int size_bin)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
struct sample_node *sn = ATH_NODE_SAMPLE(an);
int current_rix, rix;
unsigned current_tt;
uint32_t mask;
current_rix = sn->current_rix[size_bin];
if (current_rix < 0) {
/* no successes yet, send at the lowest bit-rate */
/* XXX should return MCS0 if HT */
return 0;
}
current_tt = sn->stats[size_bin][current_rix].average_tx_time;
rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
mask = sn->ratemask &~ (1<<current_rix);/* don't sample current rate */
while (mask != 0) {
if ((mask & (1<<rix)) == 0) { /* not a supported rate */
nextrate:
if (++rix >= rt->rateCount)
rix = 0;
continue;
}
/* if the node is HT and the rate isn't HT, don't bother sample */
if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
(rt->info[rix].phy != IEEE80211_T_HT)) {
mask &= ~(1<<rix);
goto nextrate;
}
/* this bit-rate is always worse than the current one */
if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
mask &= ~(1<<rix);
goto nextrate;
}
/* rarely sample bit-rates that fail a lot */
if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
mask &= ~(1<<rix);
goto nextrate;
}
/*
* When doing aggregation, successive failures don't happen
* as often, as sometimes some of the sub-frames get through.
*
* If the sample rix average tx time is greater than the
* average tx time of the current rix, don't immediately use
* the rate for sampling.
*/
if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
if ((sn->stats[size_bin][rix].average_tx_time * 10 >
sn->stats[size_bin][current_rix].average_tx_time * 9) &&
(ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout)) {
mask &= ~(1<<rix);
goto nextrate;
}
}
/*
* XXX TODO
* For HT, limit sample somehow?
*/
/* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
mask &= ~(1<<rix);
goto nextrate;
}
}
sn->last_sample_rix[size_bin] = rix;
return rix;
}
return current_rix;
#undef DOT11RATE
#undef MCS
}
/*
* Initialize the tables for a node.
*/
static void
ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
{
#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
#define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
struct ath_node *an = ATH_NODE(ni);
const struct ieee80211_txparam *tp = ni->ni_txparms;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const HAL_RATE_TABLE *rt = sc->sc_currates;
#ifdef IEEE80211_DEBUG
char ethstr[ETHER_ADDRSTRLEN + 1];
#endif
int x, y, srate, rix;
KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
("curmode %u", sc->sc_curmode));
sn->sched = mrr_schedules[sc->sc_curmode];
KASSERT(sn->sched != NULL,
("no mrr schedule for mode %u", sc->sc_curmode));
sn->static_rix = -1;
if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
/*
* A fixed rate is to be used; ucastrate is the IEEE code
* for this rate (sans basic bit). Check this against the
* negotiated rate set for the node. Note the fixed rate
* may not be available for various reasons so we only
* setup the static rate index if the lookup is successful.
* XXX handle MCS
*/
for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--)
if (RATE(srate) == tp->ucastrate) {
sn->static_rix = sc->sc_rixmap[tp->ucastrate];
break;
}
#ifdef IEEE80211_DEBUG
if (sn->static_rix == -1) {
IEEE80211_NOTE(ni->ni_vap,
IEEE80211_MSG_RATECTL, ni,
"%s: ucastrate %u not found, nrates %u",
__func__, tp->ucastrate,
ni->ni_rates.rs_nrates);
}
#endif
}
/*
* Construct a bitmask of usable rates. This has all
* negotiated rates minus those marked by the hal as
* to be ignored for doing rate control.
*/
sn->ratemask = 0;
for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
rix = sc->sc_rixmap[RATE(x)];
if (rix == 0xff)
continue;
/* skip rates marked broken by hal */
if (!rt->info[rix].valid)
continue;
KASSERT(rix < SAMPLE_MAXRATES,
("rate %u has rix %d", RATE(x), rix));
sn->ratemask |= 1<<rix;
}
#ifdef IEEE80211_DEBUG
if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
uint32_t mask;
ieee80211_note(ni->ni_vap, "[%s] %s: size 1600 rate/tt",
kether_ntoa(ni->ni_macaddr, ethstr), __func__);
for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
if ((mask & 1) == 0)
continue;
kprintf(" %d/%d", DOT11RATE(rix) / 2,
calc_usecs_unicast_packet(sc, 1600, rix, 0,0));
}
kprintf("\n");
}
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
}
/*
* Pick a good "random" bit-rate to sample other than the current one.
*/
static __inline int
pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
const HAL_RATE_TABLE *rt, int size_bin)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
struct sample_node *sn = ATH_NODE_SAMPLE(an);
int current_rix, rix;
unsigned current_tt;
uint64_t mask;
current_rix = sn->current_rix[size_bin];
if (current_rix < 0) {
/* no successes yet, send at the lowest bit-rate */
/* XXX should return MCS0 if HT */
return 0;
}
current_tt = sn->stats[size_bin][current_rix].average_tx_time;
rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
while (mask != 0) {
if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */
nextrate:
if (++rix >= rt->rateCount)
rix = 0;
continue;
}
/*
* The following code stops trying to sample
* non-MCS rates when speaking to an MCS node.
* However, at least for CCK rates in 2.4GHz mode,
* the non-MCS rates MAY actually provide better
* PER at the very far edge of reception.
*
* However! Until ath_rate_form_aggr() grows
* some logic to not form aggregates if the
* selected rate is non-MCS, this won't work.
*
* So don't disable this code until you've taught
* ath_rate_form_aggr() to drop out if any of
* the selected rates are non-MCS.
*/
#if 1
/* if the node is HT and the rate isn't HT, don't bother sample */
if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
(rt->info[rix].phy != IEEE80211_T_HT)) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
#endif
/* this bit-rate is always worse than the current one */
if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
/* rarely sample bit-rates that fail a lot */
if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
/*
* For HT, only sample a few rates on either side of the
* current rix; there's quite likely a lot of them.
*/
if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
if (rix < (current_rix - 3) ||
rix > (current_rix + 3)) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
}
/* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
}
sn->last_sample_rix[size_bin] = rix;
return rix;
}
return current_rix;
#undef DOT11RATE
#undef MCS
}
