mac80211: support rx timestamps for HE rates

Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry-picked from commit 7d8e14e44f76e18d1696565569ec50ccdce963b3)

diff --git a/package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch b/package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch
new file mode 100644 (file)
index 0000000..c432d77
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch
@@ -0,0 +1,134 @@
+From: Avraham Stern <avraham.stern@intel.com>
+Date: Sun, 6 Dec 2020 14:54:45 +0200
+Subject: [PATCH] mac80211: support Rx timestamp calculation for all preamble
+ types
+
+Add support for calculating the Rx timestamp for HE frames.
+Since now all frame types are supported, allow setting the Rx
+timestamp regardless of the frame type.
+
+Signed-off-by: Avraham Stern <avraham.stern@intel.com>
+Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
+Link: https://lore.kernel.org/r/iwlwifi.20201206145305.4786559af475.Ia54486bb0a12e5351f9d5c60ef6fcda7c9e7141c@changeid
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+---
+
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -1600,13 +1600,8 @@ ieee80211_have_rx_timestamp(struct ieee8
+ {
+       WARN_ON_ONCE(status->flag & RX_FLAG_MACTIME_START &&
+                    status->flag & RX_FLAG_MACTIME_END);
+-      if (status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END))
+-              return true;
+-      /* can't handle non-legacy preamble yet */
+-      if (status->flag & RX_FLAG_MACTIME_PLCP_START &&
+-          status->encoding == RX_ENC_LEGACY)
+-              return true;
+-      return false;
++      return !!(status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END |
++                                RX_FLAG_MACTIME_PLCP_START));
+ }
+ 
+ void ieee80211_vif_inc_num_mcast(struct ieee80211_sub_if_data *sdata);
+--- a/net/mac80211/util.c
++++ b/net/mac80211/util.c
+@@ -3665,6 +3665,7 @@ u64 ieee80211_calculate_rx_timestamp(str
+       u64 ts = status->mactime;
+       struct rate_info ri;
+       u16 rate;
++      u8 n_ltf;
+ 
+       if (WARN_ON(!ieee80211_have_rx_timestamp(status)))
+               return 0;
+@@ -3675,11 +3676,58 @@ u64 ieee80211_calculate_rx_timestamp(str
+ 
+       /* Fill cfg80211 rate info */
+       switch (status->encoding) {
++      case RX_ENC_HE:
++              ri.flags |= RATE_INFO_FLAGS_HE_MCS;
++              ri.mcs = status->rate_idx;
++              ri.nss = status->nss;
++              ri.he_ru_alloc = status->he_ru;
++              if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
++                      ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
++
++              /*
++               * See P802.11ax_D6.0, section 27.3.4 for
++               * VHT PPDU format.
++               */
++              if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
++                      mpdu_offset += 2;
++                      ts += 36;
++
++                      /*
++                       * TODO:
++                       * For HE MU PPDU, add the HE-SIG-B.
++                       * For HE ER PPDU, add 8us for the HE-SIG-A.
++                       * For HE TB PPDU, add 4us for the HE-STF.
++                       * Add the HE-LTF durations - variable.
++                       */
++              }
++
++              break;
+       case RX_ENC_HT:
+               ri.mcs = status->rate_idx;
+               ri.flags |= RATE_INFO_FLAGS_MCS;
+               if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
+                       ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
++
++              /*
++               * See P802.11REVmd_D3.0, section 19.3.2 for
++               * HT PPDU format.
++               */
++              if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
++                      mpdu_offset += 2;
++                      if (status->enc_flags & RX_ENC_FLAG_HT_GF)
++                              ts += 24;
++                      else
++                              ts += 32;
++
++                      /*
++                       * Add Data HT-LTFs per streams
++                       * TODO: add Extension HT-LTFs, 4us per LTF
++                       */
++                      n_ltf = ((ri.mcs >> 3) & 3) + 1;
++                      n_ltf = n_ltf == 3 ? 4 : n_ltf;
++                      ts += n_ltf * 4;
++              }
++
+               break;
+       case RX_ENC_VHT:
+               ri.flags |= RATE_INFO_FLAGS_VHT_MCS;
+@@ -3687,6 +3735,23 @@ u64 ieee80211_calculate_rx_timestamp(str
+               ri.nss = status->nss;
+               if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
+                       ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
++
++              /*
++               * See P802.11REVmd_D3.0, section 21.3.2 for
++               * VHT PPDU format.
++               */
++              if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
++                      mpdu_offset += 2;
++                      ts += 36;
++
++                      /*
++                       * Add VHT-LTFs per streams
++                       */
++                      n_ltf = (ri.nss != 1) && (ri.nss % 2) ?
++                              ri.nss + 1 : ri.nss;
++                      ts += 4 * n_ltf;
++              }
++
+               break;
+       default:
+               WARN_ON(1);
+@@ -3710,7 +3775,6 @@ u64 ieee80211_calculate_rx_timestamp(str
+               ri.legacy = DIV_ROUND_UP(bitrate, (1 << shift));
+ 
+               if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
+-                      /* TODO: handle HT/VHT preambles */
+                       if (status->band == NL80211_BAND_5GHZ) {
+                               ts += 20 << shift;
+                               mpdu_offset += 2;