mac80211: track number of spatial streams
With VHT, a station can change the number of spatial
streams it can receive on the fly, not unlike spatial
multiplexing in HT. Prepare for that by tracking the
maximum number of spatial streams it can receive when
the connection is established.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/vht.c b/net/mac80211/vht.c
index 0fc9a2f..67436e3 100644
--- a/net/mac80211/vht.c
+++ b/net/mac80211/vht.c
@@ -74,3 +74,44 @@
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);
+}