--- /dev/null
+--- a/drivers/net/wireless/ath/ath9k/hw.c
++++ b/drivers/net/wireless/ath/ath9k/hw.c
+@@ -313,6 +313,19 @@ void ath9k_hw_get_channel_centers(struct
+ centers->synth_center + (extoff * HT40_CHANNEL_CENTER_SHIFT);
+ }
+
++static inline void ath9k_hw_disable_pll_lock_detect(struct ath_hw *ah)
++{
++ /* On AR9330 and AR9340 devices, some PHY registers must be
++ * tuned to gain better stability/performance. These registers
++ * might be changed while doing wlan reset so the registers must
++ * be reprogrammed after each reset.
++ */
++ REG_CLR_BIT(ah, AR_PHY_USB_CTRL1, BIT(20));
++ REG_RMW(ah, AR_PHY_USB_CTRL2,
++ (1 << 21) | (0xf << 22),
++ (1 << 21) | (0x3 << 22));
++}
++
+ /******************/
+ /* Chip Revisions */
+ /******************/
+@@ -1397,6 +1410,9 @@ static bool ath9k_hw_set_reset(struct at
+ if (AR_SREV_9100(ah))
+ udelay(50);
+
++ if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
++ ath9k_hw_disable_pll_lock_detect(ah);
++
+ return true;
+ }
+
+@@ -1498,6 +1514,9 @@ static bool ath9k_hw_chip_reset(struct a
+ ath9k_hw_init_pll(ah, chan);
+ ath9k_hw_set_rfmode(ah, chan);
+
++ if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
++ ath9k_hw_disable_pll_lock_detect(ah);
++
+ return true;
+ }
+
+@@ -1848,8 +1867,14 @@ static int ath9k_hw_do_fastcc(struct ath
+ if (AR_SREV_9271(ah))
+ ar9002_hw_load_ani_reg(ah, chan);
+
++ if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
++ ath9k_hw_disable_pll_lock_detect(ah);
++
+ return 0;
+ fail:
++ if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
++ ath9k_hw_disable_pll_lock_detect(ah);
++
+ return -EINVAL;
+ }
+
+@@ -2074,6 +2099,9 @@ int ath9k_hw_reset(struct ath_hw *ah, st
+ if (AR_SREV_9565(ah) && ah->shared_chain_lnadiv)
+ REG_SET_BIT(ah, AR_BTCOEX_WL_LNADIV, AR_BTCOEX_WL_LNADIV_FORCE_ON);
+
++ if (AR_SREV_9330(ah) || AR_SREV_9340(ah))
++ ath9k_hw_disable_pll_lock_detect(ah);
++
+ return 0;
+ }
+ EXPORT_SYMBOL(ath9k_hw_reset);
+--- a/drivers/net/wireless/ath/ath9k/phy.h
++++ b/drivers/net/wireless/ath/ath9k/phy.h
+@@ -48,4 +48,7 @@
+ #define AR_PHY_PLL_CONTROL 0x16180
+ #define AR_PHY_PLL_MODE 0x16184
+
++#define AR_PHY_USB_CTRL1 0x16c84
++#define AR_PHY_USB_CTRL2 0x16c88
++
+ #endif