mac80211: add more minstrel fixes
authorFelix Fietkau <nbd@nbd.name>
Thu, 1 Mar 2018 12:34:41 +0000 (13:34 +0100)
committerFelix Fietkau <nbd@nbd.name>
Thu, 1 Mar 2018 12:35:11 +0000 (13:35 +0100)
Improves 2.4 GHz throughput

Signed-off-by: Felix Fietkau <nbd@nbd.name>
package/kernel/mac80211/patches/328-mac80211-minstrel-reduce-minstrel_mcs_groups-size.patch
package/kernel/mac80211/patches/329-mac80211-minstrel-fix-using-short-preamble-CCK-rates.patch
package/kernel/mac80211/patches/336-mac80211-minstrel-fix-CCK-rate-group-streams-value.patch [new file with mode: 0644]
package/kernel/mac80211/patches/337-mac80211-minstrel-fix-sampling-reporting-of-CCK-rate.patch [new file with mode: 0644]

index d62c362..fa51f1b 100644 (file)
@@ -218,21 +218,53 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  
        /*
         * For the throughput calculation, limit the probability value to 90% to
-@@ -780,7 +784,7 @@ minstrel_calc_retransmit(struct minstrel
+@@ -755,12 +759,19 @@ minstrel_ht_tx_status(void *priv, struct
+               minstrel_ht_update_rates(mp, mi);
+ }
++static inline int
++minstrel_get_duration(int index)
++{
++      const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
++      unsigned int duration = group->duration[index % MCS_GROUP_RATES];
++      return duration << group->shift;
++}
++
+ static void
+ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
+                          int index)
+ {
+       struct minstrel_rate_stats *mrs;
+-      const struct mcs_group *group;
+       unsigned int tx_time, tx_time_rtscts, tx_time_data;
+       unsigned int cw = mp->cw_min;
+       unsigned int ctime = 0;
+@@ -779,8 +790,7 @@ minstrel_calc_retransmit(struct minstrel
+       mrs->retry_count_rtscts = 2;
        mrs->retry_updated = true;
  
-       group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
+-      group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 -      tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
-+      tx_time_data = (group->duration[index % MCS_GROUP_RATES] << group->shift) * ampdu_len / 1000;
++      tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
  
        /* Contention time for first 2 tries */
        ctime = (t_slot * cw) >> 1;
-@@ -880,14 +884,14 @@ minstrel_ht_get_max_amsdu_len(struct min
+@@ -874,20 +884,24 @@ minstrel_ht_get_max_amsdu_len(struct min
+       int group = mi->max_prob_rate / MCS_GROUP_RATES;
+       const struct mcs_group *g = &minstrel_mcs_groups[group];
+       int rate = mi->max_prob_rate % MCS_GROUP_RATES;
++      unsigned int duration;
+       /* Disable A-MSDU if max_prob_rate is bad */
+       if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
                return 1;
  
++      duration = g->duration[rate];
++      duration <<= g->shift;
++
        /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
 -      if (g->duration[rate] > MCS_DURATION(1, 0, 52))
-+      if ((g->duration[rate] << g->shift) > MCS_DURATION(1, 0, 52))
++      if (duration > MCS_DURATION(1, 0, 52))
                return 500;
  
        /*
@@ -240,28 +272,33 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
         * data packet size
         */
 -      if (g->duration[rate] > MCS_DURATION(1, 0, 104))
-+      if ((g->duration[rate] << g->shift) > MCS_DURATION(1, 0, 104))
++      if (duration > MCS_DURATION(1, 0, 104))
                return 1600;
  
        /*
-@@ -895,7 +899,7 @@ minstrel_ht_get_max_amsdu_len(struct min
+@@ -895,7 +909,7 @@ minstrel_ht_get_max_amsdu_len(struct min
         * rate success probability is less than 75%, limit A-MSDU to twice the usual
         * data packet size
         */
 -      if (g->duration[rate] > MCS_DURATION(1, 0, 260) ||
-+      if ((g->duration[rate] << g->shift) > MCS_DURATION(1, 0, 260) ||
++      if (duration > MCS_DURATION(1, 0, 260) ||
            (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
             MINSTREL_FRAC(75, 100)))
                return 3200;
-@@ -946,7 +950,7 @@ static inline int
- minstrel_get_duration(int index)
- {
-       const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
--      return group->duration[index % MCS_GROUP_RATES];
-+      return group->duration[index % MCS_GROUP_RATES] << group->shift;
+@@ -942,13 +956,6 @@ minstrel_ht_update_rates(struct minstrel
+       rate_control_set_rates(mp->hw, mi->sta, rates);
  }
  
+-static inline int
+-minstrel_get_duration(int index)
+-{
+-      const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
+-      return group->duration[index % MCS_GROUP_RATES];
+-}
+-
  static int
+ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
+ {
 --- a/net/mac80211/rc80211_minstrel_ht.h
 +++ b/net/mac80211/rc80211_minstrel_ht.h
 @@ -33,9 +33,10 @@
@@ -280,21 +317,42 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  extern const struct mcs_group minstrel_mcs_groups[];
 --- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
 +++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
-@@ -95,7 +95,7 @@ minstrel_ht_stats_dump(struct minstrel_h
+@@ -58,6 +58,7 @@ minstrel_ht_stats_dump(struct minstrel_h
+               static const int bitrates[4] = { 10, 20, 55, 110 };
+               int idx = i * MCS_GROUP_RATES + j;
+               unsigned int prob_ewmsd;
++              unsigned int duration;
+               if (!(mi->supported[i] & BIT(j)))
+                       continue;
+@@ -95,7 +96,9 @@ minstrel_ht_stats_dump(struct minstrel_h
                p += sprintf(p, "  %3u  ", idx);
  
                /* tx_time[rate(i)] in usec */
 -              tx_time = DIV_ROUND_CLOSEST(mg->duration[j], 1000);
-+              tx_time = DIV_ROUND_CLOSEST(mg->duration[j] << mg->shift, 1000);
++              duration = mg->duration[j];
++              duration <<= mg->shift;
++              tx_time = DIV_ROUND_CLOSEST(duration, 1000);
                p += sprintf(p, "%6u  ", tx_time);
  
                tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
-@@ -238,7 +238,7 @@ minstrel_ht_stats_csv_dump(struct minstr
+@@ -204,6 +207,7 @@ minstrel_ht_stats_csv_dump(struct minstr
+               static const int bitrates[4] = { 10, 20, 55, 110 };
+               int idx = i * MCS_GROUP_RATES + j;
+               unsigned int prob_ewmsd;
++              unsigned int duration;
+               if (!(mi->supported[i] & BIT(j)))
+                       continue;
+@@ -238,7 +242,10 @@ minstrel_ht_stats_csv_dump(struct minstr
                }
  
                p += sprintf(p, "%u,", idx);
 -              tx_time = DIV_ROUND_CLOSEST(mg->duration[j], 1000);
-+              tx_time = DIV_ROUND_CLOSEST(mg->duration[j] << mg->shift, 1000);
++
++              duration = mg->duration[j];
++              duration <<= mg->shift;
++              tx_time = DIV_ROUND_CLOSEST(duration, 1000);
                p += sprintf(p, "%u,", tx_time);
  
                tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
index 5b298e6..1255da9 100644 (file)
@@ -11,7 +11,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 
 --- a/net/mac80211/rc80211_minstrel_ht.c
 +++ b/net/mac80211/rc80211_minstrel_ht.c
-@@ -1265,7 +1265,8 @@ minstrel_ht_update_caps(void *priv, stru
+@@ -1268,7 +1268,8 @@ minstrel_ht_update_caps(void *priv, stru
                goto use_legacy;
  
        if (test_sta_flag(sinfo, WLAN_STA_SHORT_PREAMBLE))
diff --git a/package/kernel/mac80211/patches/336-mac80211-minstrel-fix-CCK-rate-group-streams-value.patch b/package/kernel/mac80211/patches/336-mac80211-minstrel-fix-CCK-rate-group-streams-value.patch
new file mode 100644 (file)
index 0000000..f0ffcd9
--- /dev/null
@@ -0,0 +1,20 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Thu, 1 Mar 2018 13:27:54 +0100
+Subject: [PATCH] mac80211: minstrel: fix CCK rate group streams value
+
+Fixes a harmless underflow issue when CCK rates are actively being used
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -131,7 +131,7 @@
+ #define CCK_GROUP(_s)                                 \
+       [MINSTREL_CCK_GROUP] = {                        \
+-              .streams = 0,                           \
++              .streams = 1,                           \
+               .flags = 0,                             \
+               .shift = _s,                            \
+               .duration = {                           \
diff --git a/package/kernel/mac80211/patches/337-mac80211-minstrel-fix-sampling-reporting-of-CCK-rate.patch b/package/kernel/mac80211/patches/337-mac80211-minstrel-fix-sampling-reporting-of-CCK-rate.patch
new file mode 100644 (file)
index 0000000..ff2f345
--- /dev/null
@@ -0,0 +1,57 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Thu, 1 Mar 2018 13:28:48 +0100
+Subject: [PATCH] mac80211: minstrel: fix sampling/reporting of CCK rates
+ in HT mode
+
+Long/short preamble selection cannot be sampled separately, since it
+depends on the BSS state. Because of that, sampling attempts to
+currently not used preamble modes are not counted in the statistics,
+which leads to CCK rates being sampled too often.
+
+Fix statistics accounting for long/short preamble by increasing the
+index where necessary.
+Fix excessive CCK rate sampling by dropping unsupported sample attempts.
+
+This improves throughput on 2.4 GHz channels
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -281,7 +281,8 @@ minstrel_ht_get_stats(struct minstrel_pr
+                               break;
+               /* short preamble */
+-              if (!(mi->supported[group] & BIT(idx)))
++              if ((mi->supported[group] & BIT(idx + 4)) &&
++                  (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
+                       idx += 4;
+       }
+       return &mi->groups[group].rates[idx];
+@@ -1080,18 +1081,22 @@ minstrel_ht_get_rate(void *priv, struct
+               return;
+       sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
++      sample_idx %= MCS_GROUP_RATES;
++
++      if ((sample_idx >= 4) != txrc->short_preamble)
++              return;
++
+       info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
+       rate->count = 1;
+-      if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
++      if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
+               int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
+               rate->idx = mp->cck_rates[idx];
+       } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
+               ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
+                                      sample_group->streams);
+       } else {
+-              rate->idx = sample_idx % MCS_GROUP_RATES +
+-                          (sample_group->streams - 1) * 8;
++              rate->idx = sample_idx + (sample_group->streams - 1) * 8;
+       }
+       rate->flags = sample_group->flags;