{
 #define        ATH9K_HT_CAP_MAXRXAMPDU_65536 0x3       /* 2 ^ 16 */
 #define        ATH9K_HT_CAP_MPDUDENSITY_8 0x6          /* 8 usec */
+       u8 tx_streams, rx_streams;
 
        ht_info->ht_supported = true;
        ht_info->cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 
        /* set up supported mcs set */
        memset(&ht_info->mcs, 0, sizeof(ht_info->mcs));
+       tx_streams = !(sc->tx_chainmask & (sc->tx_chainmask - 1)) ? 1 : 2;
+       rx_streams = !(sc->rx_chainmask & (sc->rx_chainmask - 1)) ? 1 : 2;
 
-       switch(sc->rx_chainmask) {
-       case 1:
-               ht_info->mcs.rx_mask[0] = 0xff;
-               break;
-       case 3:
-       case 5:
-       case 7:
-       default:
-               ht_info->mcs.rx_mask[0] = 0xff;
-               ht_info->mcs.rx_mask[1] = 0xff;
-               break;
+       if (tx_streams != rx_streams) {
+               DPRINTF(sc, ATH_DBG_CONFIG, "TX streams %d, RX streams: %d\n",
+                       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);
        }
 
-       ht_info->mcs.tx_params = IEEE80211_HT_MCS_TX_DEFINED;
+       ht_info->mcs.rx_mask[0] = 0xff;
+       if (rx_streams >= 2)
+               ht_info->mcs.rx_mask[1] = 0xff;
+
+       ht_info->mcs.tx_params |= IEEE80211_HT_MCS_TX_DEFINED;
 }
 
 static void ath9k_bss_assoc_info(struct ath_softc *sc,