ath9k_htc: add STBC TX support

All known ar7010+ar* device and current FW support STBC TX. This patch
make use of it and suggest to send STBC if peer support it.
I use wort "suggest" since currenly we have separate rate controller
in FW which will make decision based on rate and hardware.

Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/htc.h

@@ -142,6 +142,7 @@ struct ath9k_htc_target_aggr {
 #define WLAN_RC_40_FLAG  0x02
 #define WLAN_RC_SGI_FLAG 0x04
 #define WLAN_RC_HT_FLAG  0x08
+#define ATH_RC_TX_STBC_FLAG 0x20
 
 struct ath9k_htc_rateset {
 	u8 rs_nrates;

drivers/net/wireless/ath/ath9k/htc_drv_init.c

@@ -517,6 +517,9 @@ static void setup_ht_cap(struct ath9k_htc_priv *priv,
 	ath_dbg(common, CONFIG, "TX streams %d, RX streams: %d\n",
 		tx_streams, rx_streams);
 
+	if (tx_streams >= 2)
+		ht_info->cap |= IEEE80211_HT_CAP_TX_STBC;
+
 	if (tx_streams != rx_streams) {
 		ht_info->mcs.tx_params |= IEEE80211_HT_MCS_TX_RX_DIFF;
 		ht_info->mcs.tx_params |= ((tx_streams - 1) <<

drivers/net/wireless/ath/ath9k/htc_drv_main.c

@@ -627,6 +627,8 @@ static void ath9k_htc_setup_rate(struct ath9k_htc_priv *priv,
 		trate->rates.ht_rates.rs_nrates = j;
 
 		caps = WLAN_RC_HT_FLAG;
+		if (sta->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC)
+			caps |= ATH_RC_TX_STBC_FLAG;
 		if (sta->ht_cap.mcs.rx_mask[1])
 			caps |= WLAN_RC_DS_FLAG;
 		if ((sta->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&