package/kernel/mac80211/patches/subsys/342-mac80211-minstrel_ht-improve-sample-rate-selection.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sat, 26 Dec 2020 19:12:22 +0100
   3 Subject: [PATCH] mac80211: minstrel_ht: improve sample rate selection
   4
   5 Always allow sampling of rates faster than the primary max throughput rate.
   6 When the second max_tp_rate is higher than the first one, sample attempts were
   7 previously skipped, potentially causing rate control to get stuck at a slightly
   8 lower rate
   9
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12
  13 --- a/net/mac80211/rc80211_minstrel_ht.c
  14 +++ b/net/mac80211/rc80211_minstrel_ht.c
  15 @@ -1379,13 +1379,13 @@ minstrel_get_sample_rate(struct minstrel
  16         mrs = &mg->rates[sample_idx];
  17         sample_idx += sample_group * MCS_GROUP_RATES;
  18
  19 -       /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
  20 +       tp_rate1 = mi->max_tp_rate[0];
  21 +
  22 +       /* Set tp_rate2 to the second highest max_tp_rate */
  23         if (minstrel_get_duration(mi->max_tp_rate[0]) >
  24             minstrel_get_duration(mi->max_tp_rate[1])) {
  25 -               tp_rate1 = mi->max_tp_rate[1];
  26                 tp_rate2 = mi->max_tp_rate[0];
  27         } else {
  28 -               tp_rate1 = mi->max_tp_rate[0];
  29                 tp_rate2 = mi->max_tp_rate[1];
  30         }
  31