mac80211: enable STBC and LDPC for VHT rates

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/package/kernel/mac80211/patches/310-mac80211-minstrel-Enable-STBC-and-LDPC-for-VHT-Rates.patch b/package/kernel/mac80211/patches/310-mac80211-minstrel-Enable-STBC-and-LDPC-for-VHT-Rates.patch
new file mode 100644 (file)
index 0000000..25929c9
--- /dev/null
+++ b/package/kernel/mac80211/patches/310-mac80211-minstrel-Enable-STBC-and-LDPC-for-VHT-Rates.patch
@@ -0,0 +1,81 @@
+From: Chaitanya T K <chaitanya.mgit@gmail.com>
+Date: Mon, 27 Jun 2016 15:23:26 +0530
+Subject: [PATCH] mac80211: minstrel: Enable STBC and LDPC for VHT Rates
+
+If peer support reception of STBC and LDPC, enable them for better
+performance.
+
+Signed-off-by: Chaitanya TK <chaitanya.mgit@gmail.com>
+---
+
+--- a/include/linux/ieee80211.h
++++ b/include/linux/ieee80211.h
+@@ -1550,6 +1550,7 @@ struct ieee80211_vht_operation {
+ #define IEEE80211_VHT_CAP_RXSTBC_3                            0x00000300
+ #define IEEE80211_VHT_CAP_RXSTBC_4                            0x00000400
+ #define IEEE80211_VHT_CAP_RXSTBC_MASK                         0x00000700
++#define IEEE80211_VHT_CAP_RXSTBC_SHIFT                                8
+ #define IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE                       0x00000800
+ #define IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE                       0x00001000
+ #define IEEE80211_VHT_CAP_BEAMFORMEE_STS_SHIFT                  13
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -1166,13 +1166,14 @@ minstrel_ht_update_caps(void *priv, stru
+       struct minstrel_ht_sta_priv *msp = priv_sta;
+       struct minstrel_ht_sta *mi = &msp->ht;
+       struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
+-      u16 sta_cap = sta->ht_cap.cap;
++      u16 ht_cap = sta->ht_cap.cap;
+       struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
+       int use_vht;
+       int n_supported = 0;
+       int ack_dur;
+       int stbc;
+       int i;
++      bool ldpc = false;
+ 
+       /* fall back to the old minstrel for legacy stations */
+       if (!sta->ht_cap.ht_supported)
+@@ -1210,16 +1211,24 @@ minstrel_ht_update_caps(void *priv, stru
+       }
+       mi->sample_tries = 4;
+ 
+-      /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
+       if (!use_vht) {
+-              stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
++              stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
+                       IEEE80211_HT_CAP_RX_STBC_SHIFT;
+-              mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
+ 
+-              if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
+-                      mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
++              if (ht_cap & IEEE80211_HT_CAP_LDPC_CODING)
++                      ldpc = true;
++      } else {
++              stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
++                      IEEE80211_VHT_CAP_RXSTBC_SHIFT;
++
++              if (vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC)
++                      ldpc = true;
+       }
+ 
++      mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
++      if (ldpc)
++              mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
++
+       for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
+               u32 gflags = minstrel_mcs_groups[i].flags;
+               int bw, nss;
+@@ -1232,10 +1241,10 @@ minstrel_ht_update_caps(void *priv, stru
+ 
+               if (gflags & IEEE80211_TX_RC_SHORT_GI) {
+                       if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
+-                              if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
++                              if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
+                                       continue;
+                       } else {
+-                              if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
++                              if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
+                                       continue;
+                       }
+               }