package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch

   1 From: Avraham Stern <avraham.stern@intel.com>
   2 Date: Sun, 6 Dec 2020 14:54:45 +0200
   3 Subject: [PATCH] mac80211: support Rx timestamp calculation for all preamble
   4  types
   5
   6 Add support for calculating the Rx timestamp for HE frames.
   7 Since now all frame types are supported, allow setting the Rx
   8 timestamp regardless of the frame type.
   9
  10 Signed-off-by: Avraham Stern <avraham.stern@intel.com>
  11 Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
  12 Link: https://lore.kernel.org/r/iwlwifi.20201206145305.4786559af475.Ia54486bb0a12e5351f9d5c60ef6fcda7c9e7141c@changeid
  13 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  14 ---
  15
  16 --- a/net/mac80211/ieee80211_i.h
  17 +++ b/net/mac80211/ieee80211_i.h
  18 @@ -1587,13 +1587,8 @@ ieee80211_have_rx_timestamp(struct ieee8
  19  {
  20         WARN_ON_ONCE(status->flag & RX_FLAG_MACTIME_START &&
  21                      status->flag & RX_FLAG_MACTIME_END);
  22 -       if (status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END))
  23 -               return true;
  24 -       /* can't handle non-legacy preamble yet */
  25 -       if (status->flag & RX_FLAG_MACTIME_PLCP_START &&
  26 -           status->encoding == RX_ENC_LEGACY)
  27 -               return true;
  28 -       return false;
  29 +       return !!(status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END |
  30 +                                 RX_FLAG_MACTIME_PLCP_START));
  31  }
  32
  33  void ieee80211_vif_inc_num_mcast(struct ieee80211_sub_if_data *sdata);
  34 --- a/net/mac80211/util.c
  35 +++ b/net/mac80211/util.c
  36 @@ -3665,6 +3665,7 @@ u64 ieee80211_calculate_rx_timestamp(str
  37         u64 ts = status->mactime;
  38         struct rate_info ri;
  39         u16 rate;
  40 +       u8 n_ltf;
  41
  42         if (WARN_ON(!ieee80211_have_rx_timestamp(status)))
  43                 return 0;
  44 @@ -3675,11 +3676,58 @@ u64 ieee80211_calculate_rx_timestamp(str
  45
  46         /* Fill cfg80211 rate info */
  47         switch (status->encoding) {
  48 +       case RX_ENC_HE:
  49 +               ri.flags |= RATE_INFO_FLAGS_HE_MCS;
  50 +               ri.mcs = status->rate_idx;
  51 +               ri.nss = status->nss;
  52 +               ri.he_ru_alloc = status->he_ru;
  53 +               if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
  54 +                       ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
  55 +
  56 +               /*
  57 +                * See P802.11ax_D6.0, section 27.3.4 for
  58 +                * VHT PPDU format.
  59 +                */
  60 +               if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
  61 +                       mpdu_offset += 2;
  62 +                       ts += 36;
  63 +
  64 +                       /*
  65 +                        * TODO:
  66 +                        * For HE MU PPDU, add the HE-SIG-B.
  67 +                        * For HE ER PPDU, add 8us for the HE-SIG-A.
  68 +                        * For HE TB PPDU, add 4us for the HE-STF.
  69 +                        * Add the HE-LTF durations - variable.
  70 +                        */
  71 +               }
  72 +
  73 +               break;
  74         case RX_ENC_HT:
  75                 ri.mcs = status->rate_idx;
  76                 ri.flags |= RATE_INFO_FLAGS_MCS;
  77                 if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
  78                         ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
  79 +
  80 +               /*
  81 +                * See P802.11REVmd_D3.0, section 19.3.2 for
  82 +                * HT PPDU format.
  83 +                */
  84 +               if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
  85 +                       mpdu_offset += 2;
  86 +                       if (status->enc_flags & RX_ENC_FLAG_HT_GF)
  87 +                               ts += 24;
  88 +                       else
  89 +                               ts += 32;
  90 +
  91 +                       /*
  92 +                        * Add Data HT-LTFs per streams
  93 +                        * TODO: add Extension HT-LTFs, 4us per LTF
  94 +                        */
  95 +                       n_ltf = ((ri.mcs >> 3) & 3) + 1;
  96 +                       n_ltf = n_ltf == 3 ? 4 : n_ltf;
  97 +                       ts += n_ltf * 4;
  98 +               }
  99 +
 100                 break;
 101         case RX_ENC_VHT:
 102                 ri.flags |= RATE_INFO_FLAGS_VHT_MCS;
 103 @@ -3687,6 +3735,23 @@ u64 ieee80211_calculate_rx_timestamp(str
 104                 ri.nss = status->nss;
 105                 if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
 106                         ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
 107 +
 108 +               /*
 109 +                * See P802.11REVmd_D3.0, section 21.3.2 for
 110 +                * VHT PPDU format.
 111 +                */
 112 +               if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
 113 +                       mpdu_offset += 2;
 114 +                       ts += 36;
 115 +
 116 +                       /*
 117 +                        * Add VHT-LTFs per streams
 118 +                        */
 119 +                       n_ltf = (ri.nss != 1) && (ri.nss % 2) ?
 120 +                               ri.nss + 1 : ri.nss;
 121 +                       ts += 4 * n_ltf;
 122 +               }
 123 +
 124                 break;
 125         default:
 126                 WARN_ON(1);
 127 @@ -3710,7 +3775,6 @@ u64 ieee80211_calculate_rx_timestamp(str
 128                 ri.legacy = DIV_ROUND_UP(bitrate, (1 << shift));
 129
 130                 if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
 131 -                       /* TODO: handle HT/VHT preambles */
 132                         if (status->band == NL80211_BAND_5GHZ) {
 133                                 ts += 20 << shift;
 134                                 mpdu_offset += 2;