diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index ccd819a4a816a95d1812f5a8a288027b84dd8cea..fd146c8d4cd837b2f409a481099b6ba7ad34e6f9 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -836,13 +836,16 @@ u32 ath9k_regd_get_ctl(struct ath_regulatory *reg, struct ath9k_channel *chan)
 
 static inline void ath9k_hw_set_dma(struct ath_hw *ah)
 {
+	struct ath_common *common = ath9k_hw_common(ah);
 	u32 regval;
 
 	/*
 	 * set AHB_MODE not to do cacheline prefetches
 	*/
-	regval = REG_READ(ah, AR_AHB_MODE);
-	REG_WRITE(ah, AR_AHB_MODE, regval | AR_AHB_PREFETCH_RD_EN);
+	if (!AR_SREV_9300_20_OR_LATER(ah)) {
+		regval = REG_READ(ah, AR_AHB_MODE);
+		REG_WRITE(ah, AR_AHB_MODE, regval | AR_AHB_PREFETCH_RD_EN);
+	}
 
 	/*
 	 * let mac dma reads be in 128 byte chunks
@@ -855,7 +858,8 @@ static inline void ath9k_hw_set_dma(struct ath_hw *ah)
 	 * The initial value depends on whether aggregation is enabled, and is
 	 * adjusted whenever underruns are detected.
 	 */
-	REG_RMW_FIELD(ah, AR_TXCFG, AR_FTRIG, ah->tx_trig_level);
+	if (!AR_SREV_9300_20_OR_LATER(ah))
+		REG_RMW_FIELD(ah, AR_TXCFG, AR_FTRIG, ah->tx_trig_level);
 
 	/*
 	 * let mac dma writes be in 128 byte chunks
@@ -868,6 +872,14 @@ static inline void ath9k_hw_set_dma(struct ath_hw *ah)
 	 */
 	REG_WRITE(ah, AR_RXFIFO_CFG, 0x200);
 
+	if (AR_SREV_9300_20_OR_LATER(ah)) {
+		REG_RMW_FIELD(ah, AR_RXBP_THRESH, AR_RXBP_THRESH_HP, 0x1);
+		REG_RMW_FIELD(ah, AR_RXBP_THRESH, AR_RXBP_THRESH_LP, 0x1);
+
+		ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
+			ah->caps.rx_status_len);
+	}
+
 	/*
 	 * reduce the number of usable entries in PCU TXBUF to avoid
 	 * wrap around issues.
diff --git a/drivers/net/wireless/ath/ath9k/reg.h b/drivers/net/wireless/ath/ath9k/reg.h
index 12f16215c588995635a400e57e91024a6832285a..2ca478c802c43ac478f292ef8caa3e56ac27105d 100644
--- a/drivers/net/wireless/ath/ath9k/reg.h
+++ b/drivers/net/wireless/ath/ath9k/reg.h
@@ -39,6 +39,12 @@
 #define AR_CFG_PCI_MASTER_REQ_Q_THRESH         0x00060000
 #define AR_CFG_PCI_MASTER_REQ_Q_THRESH_S       17
 
+#define AR_RXBP_THRESH       0x0018
+#define AR_RXBP_THRESH_HP    0x0000000f
+#define AR_RXBP_THRESH_HP_S  0
+#define AR_RXBP_THRESH_LP    0x00003f00
+#define AR_RXBP_THRESH_LP_S  8
+
 #define AR_MIRT              0x0020
 #define AR_MIRT_VAL          0x0000ffff
 #define AR_MIRT_VAL_S        16