mac80211: minstrel_ht: pick only supported rates for sta and group max*rates

minstrel_ht initializes max_tp_rate max_tp_rate2 and max_prob_rate to
zero both for minstrel_ht_sta and minstrel_mcs_group_data.
This is wrong since there is no guarantee that the 1st rate of any
group is supported.

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index d2b264d1311d..a23a5cff0af5 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -244,6 +244,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
         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,
@@ -254,11 +255,10 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 
         mi->sample_slow = 0;
         mi->sample_count = 0;
-        mi->max_tp_rate = 0;
-        mi->max_tp_rate2 = 0;
-        mi->max_prob_rate = 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;
@@ -268,15 +268,24 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
                 if (!mg->supported)
                         continue;
 
-                mg->max_tp_rate = 0;
-                mg->max_tp_rate2 = 0;
-                mg->max_prob_rate = 0;
                 mi->sample_count++;
 
                 for (i = 0; i < MCS_GROUP_RATES; i++) {
                         if (!(mg->supported & BIT(i)))
                                 continue;
 
+                        /* 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_rates_valid = true;
+                                }
+                                mg_rates_valid = true;
+                        }
+
                         mr = &mg->rates[i];
                         mr->retry_updated = false;
                         index = MCS_GROUP_RATES * group + i;