1 files changed, 41 insertions, 0 deletions

diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c
index 0fc9a2fb8d53..67436e3efbbd 100644
--- a/net/mac80211/vht.c
+++ b/net/mac80211/vht.c
@@ -74,3 +74,44 @@ enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct sta_info *sta)
                 return IEEE80211_STA_RX_BW_80;
         }
 }
+
+void ieee80211_sta_set_rx_nss(struct sta_info *sta)
+{
+        u8 ht_rx_nss = 0, vht_rx_nss = 0;
+
+        /* if we received a notification already don't overwrite it */
+        if (sta->sta.rx_nss)
+                return;
+
+        if (sta->sta.ht_cap.ht_supported) {
+                if (sta->sta.ht_cap.mcs.rx_mask[0])
+                        ht_rx_nss++;
+                if (sta->sta.ht_cap.mcs.rx_mask[1])
+                        ht_rx_nss++;
+                if (sta->sta.ht_cap.mcs.rx_mask[2])
+                        ht_rx_nss++;
+                if (sta->sta.ht_cap.mcs.rx_mask[3])
+                        ht_rx_nss++;
+                /* FIXME: consider rx_highest? */
+        }
+
+        if (sta->sta.vht_cap.vht_supported) {
+                int i;
+                u16 rx_mcs_map;
+
+                rx_mcs_map = le16_to_cpu(sta->sta.vht_cap.vht_mcs.rx_mcs_map);
+
+                for (i = 7; i >= 0; i--) {
+                        u8 mcs = (rx_mcs_map >> (2 * i)) & 3;
+
+                        if (mcs != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
+                                vht_rx_nss = i + 1;
+                                break;
+                        }
+                }
+                /* FIXME: consider rx_highest? */
+        }
+
+        ht_rx_nss = max(ht_rx_nss, vht_rx_nss);
+        sta->sta.rx_nss = max_t(u8, 1, ht_rx_nss);
+}