9 files changed, 45 insertions, 5 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index 3161a5901a7a..4aecc10cb3a6 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 656d8ce251a7..b34a9e91edd8 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 6f90acc5cca7..efba413561a4 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 30724a4e8bb2..47bedd82e9a9 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 3c99830dab0c..7755fb996caa 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 883f6cc7b82c..b4396a9578e5 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 cc8f3b9af71f..5fcfa48a45df 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 50bdb5db23b4..df1bfcfeb734 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 177a7b1de322..821d3679c6ff 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);
         }