@@ -135,7 +135,7 @@ minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
static int
minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
{
- return GROUP_IDX((rate->idx / 8) + 1,
+ return GROUP_IDX((rate->idx / MCS_GROUP_RATES) + 1,
!!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
!!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
}
@@ -233,12 +233,151 @@ minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
}
/*
+ * Find & sort topmost throughput rates
+ *
+ * If multiple rates provide equal throughput the sorting is based on their
+ * current success probability. Higher success probability is preferred among
+ * MCS groups, CCK rates do not provide aggregation and are therefore at last.
+ */
+static void
+minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u8 index,
+ u8 *tp_list)
+{
+ int cur_group, cur_idx, cur_thr, cur_prob;
+ int tmp_group, tmp_idx, tmp_thr, tmp_prob;
+ int j = MAX_THR_RATES;
+
+ cur_group = index / MCS_GROUP_RATES;
+ cur_idx = index % MCS_GROUP_RATES;
+ cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp;
+ cur_prob = mi->groups[cur_group].rates[cur_idx].probability;
+
+ tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
+ tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
+ tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
+ tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
+
+ while (j > 0 && (cur_thr > tmp_thr ||
+ (cur_thr == tmp_thr && cur_prob > tmp_prob))) {
+ j--;
+ tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
+ tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
+ tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
+ tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
+ }
+
+ if (j < MAX_THR_RATES - 1) {
+ memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
+ (MAX_THR_RATES - (j + 1))));
+ }
+ if (j < MAX_THR_RATES)
+ tp_list[j] = index;
+}
+
+/*
+ * Find and set the topmost probability rate per sta and per group
+ */
+static void
+minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u8 index)
+{
+ struct minstrel_mcs_group_data *mg;
+ struct minstrel_rate_stats *mr;
+ int tmp_group, tmp_idx, tmp_tp, tmp_prob, max_tp_group;
+
+ mg = &mi->groups[index / MCS_GROUP_RATES];
+ mr = &mg->rates[index % MCS_GROUP_RATES];
+
+ tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
+ tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
+ tmp_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
+ tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
+
+ /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
+ * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
+ max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
+ if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
+ (max_tp_group != MINSTREL_CCK_GROUP))
+ return;
+
+ if (mr->probability > MINSTREL_FRAC(75, 100)) {
+ if (mr->cur_tp > tmp_tp)
+ mi->max_prob_rate = index;
+ if (mr->cur_tp > mg->rates[mg->max_group_prob_rate].cur_tp)
+ mg->max_group_prob_rate = index;
+ } else {
+ if (mr->probability > tmp_prob)
+ mi->max_prob_rate = index;
+ if (mr->probability > mg->rates[mg->max_group_prob_rate].probability)
+ mg->max_group_prob_rate = index;
+ }
+}
+
+
+/*
+ * Assign new rate set per sta and use CCK rates only if the fastest
+ * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
+ * rate sets where MCS and CCK rates are mixed, because CCK rates can
+ * not use aggregation.
+ */
+static void
+minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
+ u8 tmp_mcs_tp_rate[MAX_THR_RATES],
+ u8 tmp_cck_tp_rate[MAX_THR_RATES])
+{
+ unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp;
+ int i;
+
+ tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
+ tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
+ tmp_cck_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
+
+ tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
+ tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
+ tmp_mcs_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
+
+ if (tmp_cck_tp > tmp_mcs_tp) {
+ for(i = 0; i < MAX_THR_RATES; i++) {
+ minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
+ tmp_mcs_tp_rate);
+ }
+ }
+
+}
+
+/*
+ * Try to increase robustness of max_prob rate by decrease number of
+ * streams if possible.
+ */
+static inline void
+minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
+{
+ struct minstrel_mcs_group_data *mg;
+ struct minstrel_rate_stats *mr;
+ int tmp_max_streams, group;
+ int tmp_tp = 0;
+
+ tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
+ MCS_GROUP_RATES].streams;
+ for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
+ mg = &mi->groups[group];
+ if (!mg->supported || group == MINSTREL_CCK_GROUP)
+ continue;
+ mr = minstrel_get_ratestats(mi, mg->max_group_prob_rate);
+ if (tmp_tp < mr->cur_tp &&
+ (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
+ mi->max_prob_rate = mg->max_group_prob_rate;
+ tmp_tp = mr->cur_tp;
+ }
+ }
+}
+
+/*
* Update rate statistics and select new primary rates
*
* Rules for rate selection:
* - max_prob_rate must use only one stream, as a tradeoff between delivery
* probability and throughput during strong fluctuations
- * - as long as the max prob rate has a probability of more than 3/4, pick
+ * - as long as the max prob rate has a probability of more than 75%, pick
* higher throughput rates, even if the probablity is a bit lower
*/
static void
@@ -246,9 +385,9 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
{
struct minstrel_mcs_group_data *mg;
struct minstrel_rate_stats *mr;
- int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
- int group, i, index;
- bool mi_rates_valid = false;
+ int group, i, j;
+ u8 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
+ u8 tmp_cck_tp_rate[MAX_THR_RATES], index;
if (mi->ampdu_packets > 0) {
mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
@@ -260,13 +399,14 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
mi->sample_slow = 0;
mi->sample_count = 0;
- for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
- bool mg_rates_valid = false;
+ /* Initialize global rate indexes */
+ for(j = 0; j < MAX_THR_RATES; j++){
+ tmp_mcs_tp_rate[j] = 0;
+ tmp_cck_tp_rate[j] = 0;
+ }
- cur_prob = 0;
- cur_prob_tp = 0;
- cur_tp = 0;
- cur_tp2 = 0;
+ /* Find best rate sets within all MCS groups*/
+ for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
mg = &mi->groups[group];
if (!mg->supported)
@@ -274,24 +414,16 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
mi->sample_count++;
+ /* (re)Initialize group rate indexes */
+ for(j = 0; j < MAX_THR_RATES; j++)
+ tmp_group_tp_rate[j] = group;
+
for (i = 0; i < MCS_GROUP_RATES; i++) {
if (!(mg->supported & BIT(i)))
continue;
index = MCS_GROUP_RATES * group + i;
- /* initialize rates selections starting indexes */
- if (!mg_rates_valid) {
- mg->max_tp_rate = mg->max_tp_rate2 =
- mg->max_prob_rate = i;
- if (!mi_rates_valid) {
- mi->max_tp_rate = mi->max_tp_rate2 =
- mi->max_prob_rate = index;
- mi_rates_valid = true;
- }
- mg_rates_valid = true;
- }
-
mr = &mg->rates[i];
mr->retry_updated = false;
minstrel_calc_rate_ewma(mr);
@@ -300,82 +432,47 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
if (!mr->cur_tp)
continue;
- if ((mr->cur_tp > cur_prob_tp && mr->probability >
- MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
- mg->max_prob_rate = index;
- cur_prob = mr->probability;
- cur_prob_tp = mr->cur_tp;
- }
-
- if (mr->cur_tp > cur_tp) {
- swap(index, mg->max_tp_rate);
- cur_tp = mr->cur_tp;
- mr = minstrel_get_ratestats(mi, index);
- }
-
- if (index >= mg->max_tp_rate)
- continue;
-
- if (mr->cur_tp > cur_tp2) {
- mg->max_tp_rate2 = index;
- cur_tp2 = mr->cur_tp;
+ /* Find max throughput rate set */
+ if (group != MINSTREL_CCK_GROUP) {
+ minstrel_ht_sort_best_tp_rates(mi, index,
+ tmp_mcs_tp_rate);
+ } else if (group == MINSTREL_CCK_GROUP) {
+ minstrel_ht_sort_best_tp_rates(mi, index,
+ tmp_cck_tp_rate);
}
- }
- }
- /* try to sample all available rates during each interval */
- mi->sample_count *= 8;
+ /* Find max throughput rate set within a group */
+ minstrel_ht_sort_best_tp_rates(mi, index,
+ tmp_group_tp_rate);
- cur_prob = 0;
- cur_prob_tp = 0;
- cur_tp = 0;
- cur_tp2 = 0;
- for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
- mg = &mi->groups[group];
- if (!mg->supported)
- continue;
-
- mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
- if (cur_tp < mr->cur_tp) {
- mi->max_tp_rate2 = mi->max_tp_rate;
- cur_tp2 = cur_tp;
- mi->max_tp_rate = mg->max_tp_rate;
- cur_tp = mr->cur_tp;
- mi->max_prob_streams = minstrel_mcs_groups[group].streams - 1;
+ /* Find max probability rate per group and global */
+ minstrel_ht_set_best_prob_rate(mi, index);
}
- mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
- if (cur_tp2 < mr->cur_tp) {
- mi->max_tp_rate2 = mg->max_tp_rate2;
- cur_tp2 = mr->cur_tp;
- }
+ memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
+ sizeof(mg->max_group_tp_rate));
}
- if (mi->max_prob_streams < 1)
- mi->max_prob_streams = 1;
+ /* Assign new rate set per sta */
+ minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
+ memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
- for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
- mg = &mi->groups[group];
- if (!mg->supported)
- continue;
- mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
- if (cur_prob_tp < mr->cur_tp &&
- minstrel_mcs_groups[group].streams <= mi->max_prob_streams) {
- mi->max_prob_rate = mg->max_prob_rate;
- cur_prob = mr->cur_prob;
- cur_prob_tp = mr->cur_tp;
- }
- }
+ /* Try to increase robustness of max_prob_rate*/
+ minstrel_ht_prob_rate_reduce_streams(mi);
+
+ /* try to sample all available rates during each interval */
+ mi->sample_count *= 8;
#ifdef CONFIG_MAC80211_DEBUGFS
/* use fixed index if set */
if (mp->fixed_rate_idx != -1) {
- mi->max_tp_rate = mp->fixed_rate_idx;
- mi->max_tp_rate2 = mp->fixed_rate_idx;
+ for (i = 0; i < 4; i++)
+ mi->max_tp_rate[i] = mp->fixed_rate_idx;
mi->max_prob_rate = mp->fixed_rate_idx;
}
#endif
+ /* Reset update timer */
mi->stats_update = jiffies;
}
@@ -420,8 +517,7 @@ minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
}
static void
-minstrel_downgrade_rate(struct minstrel_ht_sta *mi, unsigned int *idx,
- bool primary)
+minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u8 *idx, bool primary)
{
int group, orig_group;
@@ -437,9 +533,9 @@ minstrel_downgrade_rate(struct minstrel_ht_sta *mi, unsigned int *idx,
continue;
if (primary)
- *idx = mi->groups[group].max_tp_rate;
+ *idx = mi->groups[group].max_group_tp_rate[0];
else
- *idx = mi->groups[group].max_tp_rate2;
+ *idx = mi->groups[group].max_group_tp_rate[1];
break;
}
}
@@ -524,19 +620,19 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
* check for sudden death of spatial multiplexing,
* downgrade to a lower number of streams if necessary.
*/
- rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
+ rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
if (rate->attempts > 30 &&
MINSTREL_FRAC(rate->success, rate->attempts) <
MINSTREL_FRAC(20, 100)) {
- minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
+ minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
update = true;
}
- rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
+ rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
if (rate2->attempts > 30 &&
MINSTREL_FRAC(rate2->success, rate2->attempts) <
MINSTREL_FRAC(20, 100)) {
- minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
+ minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
update = true;
}
@@ -661,12 +757,12 @@ minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
if (!rates)
return;
- /* Start with max_tp_rate */
- minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate);
+ /* Start with max_tp_rate[0] */
+ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
if (mp->hw->max_rates >= 3) {
- /* At least 3 tx rates supported, use max_tp_rate2 next */
- minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate2);
+ /* At least 3 tx rates supported, use max_tp_rate[1] next */
+ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
}
if (mp->hw->max_rates >= 2) {
@@ -691,7 +787,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
{
struct minstrel_rate_stats *mr;
struct minstrel_mcs_group_data *mg;
- unsigned int sample_dur, sample_group;
+ unsigned int sample_dur, sample_group, cur_max_tp_streams;
int sample_idx = 0;
if (mi->sample_wait > 0) {
@@ -718,8 +814,8 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
* to the frame. Hence, don't use sampling for the currently
* used rates.
*/
- if (sample_idx == mi->max_tp_rate ||
- sample_idx == mi->max_tp_rate2 ||
+ if (sample_idx == mi->max_tp_rate[0] ||
+ sample_idx == mi->max_tp_rate[1] ||
sample_idx == mi->max_prob_rate)
return -1;
@@ -734,9 +830,12 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
* Make sure that lower rates get sampled only occasionally,
* if the link is working perfectly.
*/
+
+ cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
+ MCS_GROUP_RATES].streams;
sample_dur = minstrel_get_duration(sample_idx);
- if (sample_dur >= minstrel_get_duration(mi->max_tp_rate2) &&
- (mi->max_prob_streams <
+ if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
+ (cur_max_tp_streams - 1 <
minstrel_mcs_groups[sample_group].streams ||
sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
if (mr->sample_skipped < 20)
@@ -1041,8 +1140,8 @@ static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
if (!msp->is_ht)
return mac80211_minstrel.get_expected_throughput(priv_sta);
- i = mi->max_tp_rate / MCS_GROUP_RATES;
- j = mi->max_tp_rate % MCS_GROUP_RATES;
+ i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
+ j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
/* convert cur_tp from pkt per second in kbps */
return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024;
@@ -33,10 +33,9 @@ struct minstrel_mcs_group_data {
/* bitfield of supported MCS rates of this group */
u8 supported;
- /* selected primary rates */
- unsigned int max_tp_rate;
- unsigned int max_tp_rate2;
- unsigned int max_prob_rate;
+ /* sorted rate set within a MCS group*/
+ u8 max_group_tp_rate[MAX_THR_RATES];
+ u8 max_group_prob_rate;
/* MCS rate statistics */
struct minstrel_rate_stats rates[MCS_GROUP_RATES];
@@ -52,15 +51,9 @@ struct minstrel_ht_sta {
/* ampdu length (EWMA) */
unsigned int avg_ampdu_len;
- /* best throughput rate */
- unsigned int max_tp_rate;
-
- /* second best throughput rate */
- unsigned int max_tp_rate2;
-
- /* best probability rate */
- unsigned int max_prob_rate;
- unsigned int max_prob_streams;
+ /* overall sorted rate set */
+ u8 max_tp_rate[MAX_THR_RATES];
+ u8 max_prob_rate;
/* time of last status update */
unsigned long stats_update;
@@ -46,8 +46,10 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
else
p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
- *(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
- *(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
+ *(p++) = (idx == mi->max_tp_rate[0]) ? 'A' : ' ';
+ *(p++) = (idx == mi->max_tp_rate[1]) ? 'B' : ' ';
+ *(p++) = (idx == mi->max_tp_rate[2]) ? 'C' : ' ';
+ *(p++) = (idx == mi->max_tp_rate[3]) ? 'D' : ' ';
*(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
if (i == max_mcs) {
@@ -100,8 +102,8 @@ minstrel_ht_stats_open(struct inode *inode, struct file *file)
file->private_data = ms;
p = ms->buf;
- p += sprintf(p, "type rate throughput ewma prob this prob "
- "retry this succ/attempt success attempts\n");
+ p += sprintf(p, "type rate throughput ewma prob "
+ "this prob retry this succ/attempt success attempts\n");
p = minstrel_ht_stats_dump(mi, max_mcs, p);
for (i = 0; i < max_mcs; i++)