mac80211: minstrel_ht: fix rates selection

When initializing rates selections starting indexes upon stats update,
the minstrel_sta->max_* rates should be 'group * MCS_GROUP_RATES + i'
not 'i'. This affects settings where one of the peers does not support
any of the rates of the group 0 (i.e. when ht_cap.mcs.rx_mask[0] == 0).

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rc80211_minstrel_ht.c

@@ -277,13 +277,15 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 			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 = i;
+						mi->max_prob_rate = index;
 					mi_rates_valid = true;
 				}
 				mg_rates_valid = true;
@@ -291,7 +293,6 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 
 			mr = &mg->rates[i];
 			mr->retry_updated = false;
-			index = MCS_GROUP_RATES * group + i;
 			minstrel_calc_rate_ewma(mr);
 			minstrel_ht_calc_tp(mi, group, i);