mac80211: add new minstrel_ht patches to improve probing on mt76x2

Signed-off-by: Felix Fietkau <[email protected]>

package/kernel/mac80211/patches/subsys/363-mac80211-minstrel_ht-fix-per-group-max-throughput-ra.patch

@@ -0,0 +1,22 @@
+From: Felix Fietkau <[email protected]>
+Date: Fri, 14 Jun 2019 21:12:04 +0200
+Subject: [PATCH] mac80211: minstrel_ht: fix per-group max throughput rate
+ initialization
+
+The group number needs to be multiplied by the number of rates per group
+to get the full rate index
+
+Signed-off-by: Felix Fietkau <[email protected]>
+---
+
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -576,7 +576,7 @@ minstrel_ht_update_stats(struct minstrel
+
+ 		/* (re)Initialize group rate indexes */
+ 		for(j = 0; j < MAX_THR_RATES; j++)
+-			tmp_group_tp_rate[j] = group;
++			tmp_group_tp_rate[j] = MCS_GROUP_RATES * group;
+
+ 		for (i = 0; i < MCS_GROUP_RATES; i++) {
+ 			if (!(mi->supported[group] & BIT(i)))

package/kernel/mac80211/patches/subsys/364-mac80211-minstrel_ht-reduce-unnecessary-rate-probing.patch

@@ -0,0 +1,42 @@
+From: Felix Fietkau <[email protected]>
+Date: Wed, 5 Jun 2019 20:42:49 +0200
+Subject: [PATCH] mac80211: minstrel_ht: reduce unnecessary rate probing
+ attempts
+
+On hardware with static fallback tables (e.g. mt76x2), rate probing attempts
+can be very expensive.
+On such devices, avoid sampling rates slower than the per-group max throughput
+rate, based on the assumption that the fallback table will take care of probing
+lower rates within that group if the higher rates fail.
+To make this work, this also fixes a wrong initialization in the previously
+unused per-group sorted rate array.
+To further reduce unnecessary probing attempts, skip duplicate attempts on
+rates slower than the max throughput rate.
+
+Signed-off-by: Felix Fietkau <[email protected]>
+---
+
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -1062,6 +1062,21 @@ minstrel_get_sample_rate(struct minstrel
+ 	    minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
+ 		return -1;
+
++
++	/*
++	 * For devices with no configurable multi-rate retry, skip sampling
++	 * below the per-group max throughput rate, and only use one sampling
++	 * attempt per rate
++	 */
++	if (mp->hw->max_rates == 1 &&
++	    (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur ||
++	     mrs->attempts))
++		return -1;
++
++	/* Skip already sampled slow rates */
++	if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts)
++		return -1;
++
+ 	/*
+ 	 * Make sure that lower rates get sampled only occasionally,
+ 	 * if the link is working perfectly.

package/kernel/mac80211/patches/subsys/365-mac80211-minstrel_ht-fix-default-max-throughput-rate.patch

@@ -0,0 +1,46 @@
+From: Felix Fietkau <[email protected]>
+Date: Fri, 14 Jun 2019 21:14:22 +0200
+Subject: [PATCH] mac80211: minstrel_ht: fix default max throughput rate
+ indexes
+
+Use the first supported rate instead of 0 (which can be invalid)
+
+Signed-off-by: Felix Fietkau <[email protected]>
+---
+
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -487,7 +487,7 @@ minstrel_ht_assign_best_tp_rates(struct
+ 	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+ 	tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
+
+-	if (tmp_cck_tp > tmp_mcs_tp) {
++	if (tmp_cck_tp_rate && 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);
+@@ -559,11 +559,19 @@ minstrel_ht_update_stats(struct minstrel
+ 	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;
+-	}
++	memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate));
++	memset(tmp_cck_tp_rate, 0, sizeof(tmp_cck_tp_rate));
++	if (mi->supported[MINSTREL_CCK_GROUP])
++		for (j = 0; j < ARRAY_SIZE(tmp_cck_tp_rate); j++)
++			tmp_cck_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
++
++	if (mi->supported[MINSTREL_VHT_GROUP_0])
++		index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES;
++	else
++		index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES;
++
++	for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
++		tmp_mcs_tp_rate[j] = index;
+
+ 	/* Find best rate sets within all MCS groups*/
+ 	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {