git.openwrt.org Git - openwrt/staging/ldir.git/blob

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Wed, 6 Aug 2025 10:49:54 +0200
   3 Subject: [PATCH] mac80211: factor out part of
   4  ieee80211_calc_expected_tx_airtime
   5
   6 Create ieee80211_rate_expected_tx_airtime helper function, which returns
   7 the expected tx airtime for a given rate and packet length in units of
   8 1024 usec, for more accuracy.
   9
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12
  13 --- a/net/mac80211/airtime.c
  14 +++ b/net/mac80211/airtime.c
  15 @@ -685,7 +685,7 @@ static int ieee80211_fill_rx_status(stru
  16         if (ieee80211_fill_rate_info(hw, stat, band, ri))
  17                 return 0;
  18
  19 -       if (!ieee80211_rate_valid(rate))
  20 +       if (!rate || !ieee80211_rate_valid(rate))
  21                 return -1;
  22
  23         if (rate->flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
  24 @@ -753,6 +753,53 @@ u32 ieee80211_calc_tx_airtime(struct iee
  25  }
  26  EXPORT_SYMBOL_GPL(ieee80211_calc_tx_airtime);
  27
  28 +u32 ieee80211_rate_expected_tx_airtime(struct ieee80211_hw *hw,
  29 +                                      struct ieee80211_tx_rate *tx_rate,
  30 +                                      struct rate_info *ri,
  31 +                                      enum nl80211_band band,
  32 +                                      bool ampdu, int len)
  33 +{
  34 +       struct ieee80211_rx_status stat;
  35 +       u32 duration, overhead;
  36 +       u8 agg_shift;
  37 +
  38 +       if (ieee80211_fill_rx_status(&stat, hw, tx_rate, ri, band, len))
  39 +               return 0;
  40 +
  41 +       if (stat.encoding == RX_ENC_LEGACY || !ampdu)
  42 +               return ieee80211_calc_rx_airtime(hw, &stat, len) * 1024;
  43 +
  44 +       duration = ieee80211_get_rate_duration(hw, &stat, &overhead);
  45 +
  46 +       /*
  47 +        * Assume that HT/VHT transmission on any AC except VO will
  48 +        * use aggregation. Since we don't have reliable reporting
  49 +        * of aggregation length, assume an average size based on the
  50 +        * tx rate.
  51 +        * This will not be very accurate, but much better than simply
  52 +        * assuming un-aggregated tx in all cases.
  53 +        */
  54 +       if (duration > 400 * 1024) /* <= VHT20 MCS2 1S */
  55 +               agg_shift = 1;
  56 +       else if (duration > 250 * 1024) /* <= VHT20 MCS3 1S or MCS1 2S */
  57 +               agg_shift = 2;
  58 +       else if (duration > 150 * 1024) /* <= VHT20 MCS5 1S or MCS2 2S */
  59 +               agg_shift = 3;
  60 +       else if (duration > 70 * 1024) /* <= VHT20 MCS5 2S */
  61 +               agg_shift = 4;
  62 +       else if (stat.encoding != RX_ENC_HE ||
  63 +                duration > 20 * 1024) /* <= HE40 MCS6 2S */
  64 +               agg_shift = 5;
  65 +       else
  66 +               agg_shift = 6;
  67 +
  68 +       duration *= len;
  69 +       duration /= AVG_PKT_SIZE;
  70 +       duration += (overhead * 1024 >> agg_shift);
  71 +
  72 +       return duration;
  73 +}
  74 +
  75  u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw,
  76                                        struct ieee80211_vif *vif,
  77                                        struct ieee80211_sta *pubsta,
  78 @@ -775,45 +822,13 @@ u32 ieee80211_calc_expected_tx_airtime(s
  79         if (pubsta) {
  80                 struct sta_info *sta = container_of(pubsta, struct sta_info,
  81                                                     sta);
  82 -               struct ieee80211_rx_status stat;
  83                 struct ieee80211_tx_rate *tx_rate = &sta->deflink.tx_stats.last_rate;
  84                 struct rate_info *ri = &sta->deflink.tx_stats.last_rate_info;
  85 -               u32 duration, overhead;
  86 -               u8 agg_shift;
  87 -
  88 -               if (ieee80211_fill_rx_status(&stat, hw, tx_rate, ri, band, len))
  89 -                       return 0;
  90 -
  91 -               if (stat.encoding == RX_ENC_LEGACY || !ampdu)
  92 -                       return ieee80211_calc_rx_airtime(hw, &stat, len);
  93 -
  94 -               duration = ieee80211_get_rate_duration(hw, &stat, &overhead);
  95 -               /*
  96 -                * Assume that HT/VHT transmission on any AC except VO will
  97 -                * use aggregation. Since we don't have reliable reporting
  98 -                * of aggregation length, assume an average size based on the
  99 -                * tx rate.
 100 -                * This will not be very accurate, but much better than simply
 101 -                * assuming un-aggregated tx in all cases.
 102 -                */
 103 -               if (duration > 400 * 1024) /* <= VHT20 MCS2 1S */
 104 -                       agg_shift = 1;
 105 -               else if (duration > 250 * 1024) /* <= VHT20 MCS3 1S or MCS1 2S */
 106 -                       agg_shift = 2;
 107 -               else if (duration > 150 * 1024) /* <= VHT20 MCS5 1S or MCS2 2S */
 108 -                       agg_shift = 3;
 109 -               else if (duration > 70 * 1024) /* <= VHT20 MCS5 2S */
 110 -                       agg_shift = 4;
 111 -               else if (stat.encoding != RX_ENC_HE ||
 112 -                        duration > 20 * 1024) /* <= HE40 MCS6 2S */
 113 -                       agg_shift = 5;
 114 -               else
 115 -                       agg_shift = 6;
 116 +               u32 duration;
 117
 118 -               duration *= len;
 119 -               duration /= AVG_PKT_SIZE;
 120 +               duration = ieee80211_rate_expected_tx_airtime(hw, tx_rate, ri,
 121 +                                                             band, true, len);
 122                 duration /= 1024;
 123 -               duration += (overhead >> agg_shift);
 124
 125                 return max_t(u32, duration, 4);
 126         }
 127 --- a/net/mac80211/ieee80211_i.h
 128 +++ b/net/mac80211/ieee80211_i.h
 129 @@ -2776,6 +2776,11 @@ u8 *ieee80211_get_bssid(struct ieee80211
 130
 131  extern const struct ethtool_ops ieee80211_ethtool_ops;
 132
 133 +u32 ieee80211_rate_expected_tx_airtime(struct ieee80211_hw *hw,
 134 +                                      struct ieee80211_tx_rate *tx_rate,
 135 +                                      struct rate_info *ri,
 136 +                                      enum nl80211_band band,
 137 +                                      bool ampdu, int len);
 138  u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw,
 139                                        struct ieee80211_vif *vif,
 140                                        struct ieee80211_sta *pubsta,