Commit a7fca4e4 authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
Browse files

mac80211: minstrel_ht: fix max probability rate selection 



- do not select rates faster than the max throughput rate if probability is lower
- reset previous rate before sorting again

This ensures that the max prob rate gets set to a more reliable rate

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210115120242.89616-8-nbd@nbd.name


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 019c6fc2

net/mac80211/rc80211_minstrel_ht.c

+38 −9
Original line number Diff line number Diff line
@@ -495,12 +495,13 @@ minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 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, u16 index)

minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)

{

	struct minstrel_mcs_group_data *mg;

	struct minstrel_rate_stats *mrs;

	int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;

	int max_tp_group, cur_tp_avg, cur_group, cur_idx;

	int max_tp_group, max_tp_idx, max_tp_prob;

	int cur_tp_avg, cur_group, cur_idx;

	int max_gpr_group, max_gpr_idx;

	int max_gpr_tp_avg, max_gpr_prob;
@@ -509,18 +510,26 @@ minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 
	mg = &mi->groups[index / MCS_GROUP_RATES];

	mrs = &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_group = *dest / MCS_GROUP_RATES;

	tmp_idx = *dest % MCS_GROUP_RATES;

	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;

	tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);



	/* 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;

	max_tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES;

	max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;



	if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES) &&

	    !minstrel_ht_is_legacy_group(max_tp_group))

		return;



	/* skip rates faster than max tp rate with lower prob */

	if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&

	    mrs->prob_avg < max_tp_prob)

		return;



	max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;

	max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;

	max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
@@ -538,7 +547,7 @@ minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 
			mg->max_group_prob_rate = index;

	} else {

		if (mrs->prob_avg > tmp_prob)

			mi->max_prob_rate = index;

			*dest = index;

		if (mrs->prob_avg > max_gpr_prob)

			mg->max_group_prob_rate = index;

	}
@@ -816,7 +825,8 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
	struct minstrel_rate_stats *mrs;

	int group, i, j, cur_prob;

	u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];

	u16 tmp_legacy_tp_rate[MAX_THR_RATES], index;

	u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;

	u16 index;

	bool ht_supported = mi->sta->ht_cap.ht_supported;



	mi->sample_mode = MINSTREL_SAMPLE_IDLE;
@@ -863,6 +873,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
	else

		index = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES;



	tmp_max_prob_rate = index;

	for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)

		tmp_mcs_tp_rate[j] = index;
@@ -903,9 +914,6 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
			/* 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,
@@ -917,6 +925,27 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
					 tmp_legacy_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++) {

		if (!mi->supported[group])

			continue;



		mg = &mi->groups[group];

		mg->max_group_prob_rate = MCS_GROUP_RATES * group;



		for (i = 0; i < MCS_GROUP_RATES; i++) {

			if (!(mi->supported[group] & BIT(i)))

				continue;



			index = MCS_GROUP_RATES * group + i;



			/* Find max probability rate per group and global */

			minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,

						       index);

		}

	}



	mi->max_prob_rate = tmp_max_prob_rate;



	/* Try to increase robustness of max_prob_rate*/

	minstrel_ht_prob_rate_reduce_streams(mi);