ath9k: Store noise immunity values across scanning

CCK/OFDM noise immunilty values are always reset to defaults
during bgscan. This could affect the link quality and
performance when the STA is associated in a noisy channel.
So do not override the learned values across the scanning.
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -273,7 +273,8 @@ static void ath9k_hw_set_ofdm_nil(struct ath_hw *ah, u8 immunityLevel)
 		immunityLevel, aniState->noiseFloor,
 		aniState->rssiThrLow, aniState->rssiThrHigh);
 
-	aniState->ofdmNoiseImmunityLevel = immunityLevel;
+	if (aniState->update_ani)
+		aniState->ofdmNoiseImmunityLevel = immunityLevel;
 
 	entry_ofdm = &ofdm_level_table[aniState->ofdmNoiseImmunityLevel];
 	entry_cck = &cck_level_table[aniState->cckNoiseImmunityLevel];
@@ -346,7 +347,8 @@ static void ath9k_hw_set_cck_nil(struct ath_hw *ah, u_int8_t immunityLevel)
 	    immunityLevel > ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI)
 		immunityLevel = ATH9K_ANI_CCK_MAX_LEVEL_LOW_RSSI;
 
-	aniState->cckNoiseImmunityLevel = immunityLevel;
+	if (aniState->update_ani)
+		aniState->cckNoiseImmunityLevel = immunityLevel;
 
 	entry_ofdm = &ofdm_level_table[aniState->ofdmNoiseImmunityLevel];
 	entry_cck = &cck_level_table[aniState->cckNoiseImmunityLevel];
@@ -593,6 +595,7 @@ void ath9k_ani_reset(struct ath_hw *ah, bool is_scanning)
 				aniState->ofdmNoiseImmunityLevel,
 				aniState->cckNoiseImmunityLevel);
 
+			aniState->update_ani = false;
 			ath9k_hw_set_ofdm_nil(ah, ATH9K_ANI_OFDM_DEF_LEVEL);
 			ath9k_hw_set_cck_nil(ah, ATH9K_ANI_CCK_DEF_LEVEL);
 		}
@@ -609,6 +612,7 @@ void ath9k_ani_reset(struct ath_hw *ah, bool is_scanning)
 			aniState->ofdmNoiseImmunityLevel,
 			aniState->cckNoiseImmunityLevel);
 
+			aniState->update_ani = true;
 			ath9k_hw_set_ofdm_nil(ah,
 					      aniState->ofdmNoiseImmunityLevel);
 			ath9k_hw_set_cck_nil(ah,
@@ -892,6 +896,8 @@ void ath9k_hw_ani_init(struct ath_hw *ah)
 		ani->ofdmWeakSigDetectOff =
 			!ATH9K_ANI_USE_OFDM_WEAK_SIG;
 		ani->cckNoiseImmunityLevel = ATH9K_ANI_CCK_DEF_LEVEL;
+		ani->ofdmNoiseImmunityLevel = ATH9K_ANI_OFDM_DEF_LEVEL;
+		ani->update_ani = false;
 	}
 
 	/*

drivers/net/wireless/ath/ath9k/ani.h

@@ -122,6 +122,7 @@ struct ar5416AniState {
 	u8 firstepLevel;
 	u8 ofdmWeakSigDetectOff;
 	u8 cckWeakSigThreshold;
+	bool update_ani;
 	u32 listenTime;
 	int32_t rssiThrLow;
 	int32_t rssiThrHigh;