ath9k_htc: Setup HT capabilites for 2-stream devices

The supported MCS rate set has to be setup properly
for 2-stream devices.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_init.c b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
index ff6c0807b502..acd9cb934311 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_init.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
@@ -398,6 +398,10 @@ static const struct ath_bus_ops ath9k_usb_bus_ops = {
 static void setup_ht_cap(struct ath9k_htc_priv *priv,
                          struct ieee80211_sta_ht_cap *ht_info)
 {
+        struct ath_common *common = ath9k_hw_common(priv->ah);
+        u8 tx_streams, rx_streams;
+        int i;
+
         ht_info->ht_supported = true;
         ht_info->cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
                        IEEE80211_HT_CAP_SM_PS |
@@ -413,7 +417,24 @@ static void setup_ht_cap(struct ath9k_htc_priv *priv,
         ht_info->ampdu_density = IEEE80211_HT_MPDU_DENSITY_8;
 
         memset(&ht_info->mcs, 0, sizeof(ht_info->mcs));
-        ht_info->mcs.rx_mask[0] = 0xff;
+
+        /* ath9k_htc supports only 1 or 2 stream devices */
+        tx_streams = ath9k_cmn_count_streams(common->tx_chainmask, 2);
+        rx_streams = ath9k_cmn_count_streams(common->rx_chainmask, 2);
+
+        ath_print(common, ATH_DBG_CONFIG,
+                  "TX streams %d, RX streams: %d\n",
+                  tx_streams, rx_streams);
+
+        if (tx_streams != rx_streams) {
+                ht_info->mcs.tx_params |= IEEE80211_HT_MCS_TX_RX_DIFF;
+                ht_info->mcs.tx_params |= ((tx_streams - 1) <<
+                                           IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT);
+        }
+
+        for (i = 0; i < rx_streams; i++)
+                ht_info->mcs.rx_mask[i] = 0xff;
+
         ht_info->mcs.tx_params |= IEEE80211_HT_MCS_TX_DEFINED;
 }