/*
* 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
* higher throughput rates, even if the probablity is a bit lower
*/
static void
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;
if (mi->ampdu_packets > 0) {
mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
mi->ampdu_len = 0;
mi->ampdu_packets = 0;
}
mi->sample_slow = 0;
mi->sample_count = 0;
for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
bool mg_rates_valid = false;
cur_prob = 0;
cur_prob_tp = 0;
cur_tp = 0;
cur_tp2 = 0;
mg = &mi->groups[group];
if (!mg->supported)
continue;
mi->sample_count++;
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);
minstrel_ht_calc_tp(mi, group, i);
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;
}
}
}
/* try to sample all available rates during each interval */
mi->sample_count *= 8;
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;
}
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;
}
}
if (mi->max_prob_streams < 1)
mi->max_prob_streams = 1;
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;
}
}
#ifdef CPTCFG_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;
mi->max_prob_rate = mp->fixed_rate_idx;
}
#endif
mi->stats_update = jiffies;
}
/*
* 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 75%, pick
* higher throughput rates, even if the probablity is a bit lower
*/
static void
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 group, i, j;
u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
if (mi->ampdu_packets > 0) {
mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
mi->ampdu_len = 0;
mi->ampdu_packets = 0;
}
mi->sample_slow = 0;
mi->sample_count = 0;
/* Initialize global rate indexes */
for(j = 0; j < MAX_THR_RATES; j++){
tmp_mcs_tp_rate[j] = 0;
tmp_cck_tp_rate[j] = 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)
continue;
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;
mr = &mg->rates[i];
mr->retry_updated = false;
minstrel_calc_rate_ewma(mr);
minstrel_ht_calc_tp(mi, group, i);
if (!mr->cur_tp)
continue;
/* 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);
}
/* Find max throughput rate set within a group */
minstrel_ht_sort_best_tp_rates(mi, index,
tmp_group_tp_rate);
/* Find max probability rate per group and global */
minstrel_ht_set_best_prob_rate(mi, index);
}
memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
sizeof(mg->max_group_tp_rate));
}
/* 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));
/* 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) {
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;
}