package/kernel/mac80211/patches/subsys/383-mac80211-minstrel_ht-add-flag-to-indicate-missing-in.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Wed, 16 Jan 2019 21:47:54 +0100
   3 Subject: [PATCH] mac80211: minstrel_ht: add flag to indicate
   4  missing/inaccurate tx A-MPDU length
   5
   6 Some hardware (e.g. MediaTek MT7603) cannot report A-MPDU length in tx status
   7 information. Add support for a flag to indicate that, to allow minstrel_ht
   8 to use a fixed value in its internal calculation (which gives better results
   9 than just defaulting to 1).
  10
  11 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  12 ---
  13
  14 --- a/include/net/mac80211.h
  15 +++ b/include/net/mac80211.h
  16 @@ -2130,6 +2130,9 @@ struct ieee80211_txq {
  17   * @IEEE80211_HW_NEEDS_ALIGNED4_SKBS: Driver need aligned skbs to four-byte.
  18   *     Padding will be added after ieee80211_hdr, before IV/LLC.
  19   *
  20 + * @IEEE80211_HW_TX_STATUS_NO_AMPDU_LEN: Driver does not report accurate A-MPDU
  21 + *     length in tx status information
  22 + *
  23   * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  24   */
  25  enum ieee80211_hw_flags {
  26 @@ -2176,6 +2179,7 @@ enum ieee80211_hw_flags {
  27         IEEE80211_HW_DEAUTH_NEED_MGD_TX_PREP,
  28         IEEE80211_HW_DOESNT_SUPPORT_QOS_NDP,
  29         IEEE80211_HW_NEEDS_ALIGNED4_SKBS,
  30 +       IEEE80211_HW_TX_STATUS_NO_AMPDU_LEN,
  31
  32         /* keep last, obviously */
  33         NUM_IEEE80211_HW_FLAGS
  34 --- a/net/mac80211/debugfs.c
  35 +++ b/net/mac80211/debugfs.c
  36 @@ -215,6 +215,7 @@ static const char *hw_flag_names[] = {
  37         FLAG(DEAUTH_NEED_MGD_TX_PREP),
  38         FLAG(DOESNT_SUPPORT_QOS_NDP),
  39         FLAG(NEEDS_ALIGNED4_SKBS),
  40 +       FLAG(TX_STATUS_NO_AMPDU_LEN),
  41  #undef FLAG
  42  };
  43
  44 --- a/net/mac80211/rc80211_minstrel_ht.c
  45 +++ b/net/mac80211/rc80211_minstrel_ht.c
  46 @@ -294,6 +294,15 @@ minstrel_get_ratestats(struct minstrel_h
  47         return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
  48  }
  49
  50 +static unsigned int
  51 +minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
  52 +{
  53 +       if (!mi->avg_ampdu_len)
  54 +               return AVG_AMPDU_SIZE;
  55 +
  56 +       return MINSTREL_TRUNC(mi->avg_ampdu_len);
  57 +}
  58 +
  59  /*
  60   * Return current throughput based on the average A-MPDU length, taking into
  61   * account the expected number of retransmissions and their expected length
  62 @@ -309,7 +318,7 @@ minstrel_ht_get_tp_avg(struct minstrel_h
  63                 return 0;
  64
  65         if (group != MINSTREL_CCK_GROUP)
  66 -               nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
  67 +               nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
  68
  69         nsecs += minstrel_mcs_groups[group].duration[rate] <<
  70                  minstrel_mcs_groups[group].shift;
  71 @@ -503,8 +512,12 @@ minstrel_ht_update_stats(struct minstrel
  72         u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
  73
  74         if (mi->ampdu_packets > 0) {
  75 -               mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
  76 -                       MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
  77 +               if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
  78 +                       mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
  79 +                               MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
  80 +                                             EWMA_LEVEL);
  81 +               else
  82 +                       mi->avg_ampdu_len = 0;
  83                 mi->ampdu_len = 0;
  84                 mi->ampdu_packets = 0;
  85         }
  86 @@ -709,7 +722,9 @@ minstrel_ht_tx_status(void *priv, struct
  87         mi->ampdu_len += info->status.ampdu_len;
  88
  89         if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
  90 -               mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
  91 +               int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
  92 +
  93 +               mi->sample_wait = 16 + 2 * avg_ampdu_len;
  94                 mi->sample_tries = 1;
  95                 mi->sample_count--;
  96         }
  97 @@ -777,7 +792,7 @@ minstrel_calc_retransmit(struct minstrel
  98         unsigned int cw = mp->cw_min;
  99         unsigned int ctime = 0;
 100         unsigned int t_slot = 9; /* FIXME */
 101 -       unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
 102 +       unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
 103         unsigned int overhead = 0, overhead_rtscts = 0;
 104
 105         mrs = minstrel_get_ratestats(mi, index);
 106 --- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
 107 +++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
 108 @@ -163,9 +163,10 @@ minstrel_ht_stats_open(struct inode *ino
 109                         "lookaround %d\n",
 110                         max(0, (int) mi->total_packets - (int) mi->sample_packets),
 111                         mi->sample_packets);
 112 -       p += sprintf(p, "Average # of aggregated frames per A-MPDU: %d.%d\n",
 113 -               MINSTREL_TRUNC(mi->avg_ampdu_len),
 114 -               MINSTREL_TRUNC(mi->avg_ampdu_len * 10) % 10);
 115 +       if (mi->avg_ampdu_len)
 116 +               p += sprintf(p, "Average # of aggregated frames per A-MPDU: %d.%d\n",
 117 +                       MINSTREL_TRUNC(mi->avg_ampdu_len),
 118 +                       MINSTREL_TRUNC(mi->avg_ampdu_len * 10) % 10);
 119         ms->len = p - ms->buf;
 120         WARN_ON(ms->len + sizeof(*ms) > 32768);
 121