diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index 3161a5901a7a8d257412864fda3e35d11b454db4..4aecc10cb3a698758d395a6d564fdcf05c31404c 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -3029,6 +3029,8 @@ static u32 ath9k_hw_ar9300_get_eeprom(struct ath_hw *ah,
 		return le32_to_cpu(pBase->swreg);
 	case EEP_PAPRD:
 		return !!(pBase->featureEnable & BIT(5));
+	case EEP_CHAIN_MASK_REDUCE:
+		return (pBase->miscConfiguration >> 0x3) & 0x1;
 	default:
 		return 0;
 	}
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_phy.c b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
index 656d8ce251a7f243df8667f23775276648adfd83..b34a9e91edd80ff4616cb3f844f5c5341e09b1ef 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
@@ -487,7 +487,11 @@ void ar9003_hw_set_chain_masks(struct ath_hw *ah, u8 rx, u8 tx)
 		break;
 	}
 
-	REG_WRITE(ah, AR_SELFGEN_MASK, tx);
+	if ((ah->caps.hw_caps & ATH9K_HW_CAP_APM) && (tx == 0x7))
+		REG_WRITE(ah, AR_SELFGEN_MASK, 0x3);
+	else
+		REG_WRITE(ah, AR_SELFGEN_MASK, tx);
+
 	if (tx == 0x5) {
 		REG_SET_BIT(ah, AR_PHY_ANALOG_SWAP,
 			    AR_PHY_SWAP_ALT_CHAIN);
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 6f90acc5cca76296d7bcc7b7cb31797c7ffcfb59..efba413561a44b7e87ac8e40043e899fea469a41 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -544,6 +544,7 @@ struct ath_ant_comb {
 #define SC_OP_BT_PRIORITY_DETECTED   BIT(12)
 #define SC_OP_BT_SCAN		     BIT(13)
 #define SC_OP_ANI_RUN		     BIT(14)
+#define SC_OP_ENABLE_APM	     BIT(15)
 
 /* Powersave flags */
 #define PS_WAIT_FOR_BEACON        BIT(0)
@@ -695,6 +696,8 @@ static inline void ath_ahb_exit(void) {};
 void ath9k_ps_wakeup(struct ath_softc *sc);
 void ath9k_ps_restore(struct ath_softc *sc);
 
+u8 ath_txchainmask_reduction(struct ath_softc *sc, u8 chainmask, u32 rate);
+
 void ath9k_set_bssid_mask(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
 int ath9k_wiphy_add(struct ath_softc *sc);
 int ath9k_wiphy_del(struct ath_wiphy *aphy);
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index 30724a4e8bb2ed34b8a96db84c02493a0d911e1d..47bedd82e9a90b7c050fbcfe9d6347f83f7c2726 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -103,7 +103,8 @@ static void ath_beacon_setup(struct ath_softc *sc, struct ath_vif *avp,
 	memset(series, 0, sizeof(struct ath9k_11n_rate_series) * 4);
 	series[0].Tries = 1;
 	series[0].Rate = rate;
-	series[0].ChSel = common->tx_chainmask;
+	series[0].ChSel = ath_txchainmask_reduction(sc,
+			common->tx_chainmask, series[0].Rate);
 	series[0].RateFlags = (ctsrate) ? ATH9K_RATESERIES_RTS_CTS : 0;
 	ath9k_hw_set11n_ratescenario(ah, ds, ds, 0, ctsrate, ctsduration,
 				     series, 4, 0);
diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h b/drivers/net/wireless/ath/ath9k/eeprom.h
index 3c99830dab0c2b385725075e5d36afa05d7d44b6..7755fb996caaed6a327ecaa3841a2a8b23c14e6e 100644
--- a/drivers/net/wireless/ath/ath9k/eeprom.h
+++ b/drivers/net/wireless/ath/ath9k/eeprom.h
@@ -268,6 +268,7 @@ enum eeprom_param {
 	EEP_PAPRD,
 	EEP_MODAL_VER,
 	EEP_ANT_DIV_CTL1,
+	EEP_CHAIN_MASK_REDUCE
 };
 
 enum ar5416_rates {
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 883f6cc7b82c7efa89b9fbf55b0394db86ba4889..b4396a9578e56c3e24b52cc6b4b09e3adbadeda2 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1974,6 +1974,12 @@ int ath9k_hw_fill_cap_info(struct ath_hw *ah)
 			if ((ant_div_ctl1 & 0x1) && ((ant_div_ctl1 >> 3) & 0x1))
 				pCap->hw_caps |= ATH9K_HW_CAP_ANT_DIV_COMB;
 		}
+	if (AR_SREV_9300_20_OR_LATER(ah)) {
+		if (ah->eep_ops->get_eeprom(ah, EEP_CHAIN_MASK_REDUCE))
+			pCap->hw_caps |= ATH9K_HW_CAP_APM;
+	}
+
+
 
 	return 0;
 }
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index cc8f3b9af71f7152b31634b942ef5d6c50f68187..5fcfa48a45df9132c4f0df65ab11441a1cd23432 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -187,6 +187,7 @@ enum ath9k_hw_caps {
 	ATH9K_HW_CAP_ANT_DIV_COMB		= BIT(12),
 	ATH9K_HW_CAP_2GHZ			= BIT(13),
 	ATH9K_HW_CAP_5GHZ			= BIT(14),
+	ATH9K_HW_CAP_APM			= BIT(15),
 };
 
 struct ath9k_hw_capabilities {
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 50bdb5db23b4e1292fe20d55072353105a72fcda..df1bfcfeb7343b327bbf4a543281ee745440972e 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -554,9 +554,12 @@ void ath_update_chainmask(struct ath_softc *sc, int is_ht)
 static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta)
 {
 	struct ath_node *an;
-
+	struct ath_hw *ah = sc->sc_ah;
 	an = (struct ath_node *)sta->drv_priv;
 
+	if ((ah->caps.hw_caps) & ATH9K_HW_CAP_APM)
+		sc->sc_flags |= SC_OP_ENABLE_APM;
+
 	if (sc->sc_flags & SC_OP_TXAGGR) {
 		ath_tx_node_init(sc, an);
 		an->maxampdu = 1 << (IEEE80211_HT_MAX_AMPDU_FACTOR +
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 177a7b1de32263da4d46140c880abf64ed638f8b..821d3679c6ffe6d6d1a7133b67b57c530c80a095 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1506,6 +1506,18 @@ static u32 ath_pkt_duration(struct ath_softc *sc, u8 rix, int pktlen,
 	return duration;
 }
 
+u8 ath_txchainmask_reduction(struct ath_softc *sc, u8 chainmask, u32 rate)
+{
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath9k_channel *curchan = ah->curchan;
+	if ((sc->sc_flags & SC_OP_ENABLE_APM) &&
+			(curchan->channelFlags & CHANNEL_5GHZ) &&
+			(chainmask == 0x7) && (rate < 0x90))
+		return 0x3;
+	else
+		return chainmask;
+}
+
 static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len)
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
@@ -1546,7 +1558,6 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len)
 
 		rix = rates[i].idx;
 		series[i].Tries = rates[i].count;
-		series[i].ChSel = common->tx_chainmask;
 
 		if ((sc->config.ath_aggr_prot && bf_isaggr(bf)) ||
 		    (rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS)) {
@@ -1569,6 +1580,8 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len)
 		if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 			/* MCS rates */
 			series[i].Rate = rix | 0x80;
+			series[i].ChSel = ath_txchainmask_reduction(sc,
+					common->tx_chainmask, series[i].Rate);
 			series[i].PktDuration = ath_pkt_duration(sc, rix, len,
 				 is_40, is_sgi, is_sp);
 			if (rix < 8 && (tx_info->flags & IEEE80211_TX_CTL_STBC))
@@ -1576,7 +1589,7 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len)
 			continue;
 		}
 
-		/* legcay rates */
+		/* legacy rates */
 		if ((tx_info->band == IEEE80211_BAND_2GHZ) &&
 		    !(rate->flags & IEEE80211_RATE_ERP_G))
 			phy = WLAN_RC_PHY_CCK;
@@ -1592,6 +1605,12 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len)
 			is_sp = false;
 		}
 
+		if (bf->bf_state.bfs_paprd)
+			series[i].ChSel = common->tx_chainmask;
+		else
+			series[i].ChSel = ath_txchainmask_reduction(sc,
+					common->tx_chainmask, series[i].Rate);
+
 		series[i].PktDuration = ath9k_hw_computetxtime(sc->sc_ah,
 			phy, rate->bitrate * 100, len, rix, is_sp);
 	}