ath9k: Run the LNA combining algorithm properly

The LNA combining algorithm has to be run for cards
that support the required diversity features, make
sure that that correct conditions are met before
enabing this algorithm.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -1157,6 +1157,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 	struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
 	struct ieee80211_rx_status *rxs;
 	struct ath_hw *ah = sc->sc_ah;
+	struct ath9k_hw_capabilities *pCap = &ah->caps;
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ieee80211_hw *hw = sc->hw;
 	struct ieee80211_hdr *hdr;
@@ -1328,11 +1329,30 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 			skb = hdr_skb;
 		}
 
+		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
+			skb_trim(skb, skb->len - 8);
 
-		if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) {
+		spin_lock_irqsave(&sc->sc_pm_lock, flags);
+		if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
+				     PS_WAIT_FOR_CAB |
+				     PS_WAIT_FOR_PSPOLL_DATA)) ||
+		    ath9k_check_auto_sleep(sc))
+			ath_rx_ps(sc, skb, rs.is_mybeacon);
+		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
 
 		/*
-			 * change the default rx antenna if rx diversity
+		 * Run the LNA combining algorithm only in these cases:
+		 *
+		 * Standalone WLAN cards with both LNA/Antenna diversity
+		 * enabled in the EEPROM.
+		 *
+		 * WLAN+BT cards which are in the supported card list
+		 * in ath_pci_id_table and the user has loaded the
+		 * driver with "bt_ant_diversity" set to true.
+		 */
+		if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) {
+			/*
+			 * Change the default rx antenna if rx diversity
 			 * chooses the other antenna 3 times in a row.
 			 */
 			if (sc->rx.defant != rs.rs_antenna) {
@@ -1342,21 +1362,13 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 				sc->rx.rxotherant = 0;
 			}
 
-		}
-
-		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
-			skb_trim(skb, skb->len - 8);
-
-		spin_lock_irqsave(&sc->sc_pm_lock, flags);
-		if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
-				     PS_WAIT_FOR_CAB |
-				     PS_WAIT_FOR_PSPOLL_DATA)) ||
-		    ath9k_check_auto_sleep(sc))
-			ath_rx_ps(sc, skb, rs.is_mybeacon);
-		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
-
-		if ((ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) && sc->ant_rx == 3)
+			if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) {
+				if (common->bt_ant_diversity)
 					ath_ant_comb_scan(sc, &rs);
+			} else {
+				ath_ant_comb_scan(sc, &rs);
+			}
+		}
 
 		ath9k_apply_ampdu_details(sc, &rs, rxs);