--- a/drivers/net/wireless/ath/ath9k/calib.c
+++ b/drivers/net/wireless/ath/ath9k/calib.c
@@ -365,6 +365,7 @@ bool ath9k_hw_getnf(struct ath_hw *ah, s
 
 	if (!caldata) {
 		chan->noisefloor = nf;
+		ah->noise = ath9k_hw_getchan_noise(ah, chan);
 		return false;
 	}
 
@@ -372,6 +373,7 @@ bool ath9k_hw_getnf(struct ath_hw *ah, s
 	caldata->nfcal_pending = false;
 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
 	chan->noisefloor = h[0].privNF;
+	ah->noise = ath9k_hw_getchan_noise(ah, chan);
 	return true;
 }
 
@@ -398,10 +400,15 @@ void ath9k_init_nfcal_hist_buffer(struct
 
 s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan)
 {
-	if (!ah->curchan || !ah->curchan->noisefloor)
-		return ath9k_hw_get_default_nf(ah, chan);
+	s8 noise = ATH_DEFAULT_NOISE_FLOOR;
 
-	return ah->curchan->noisefloor;
+	if (chan && chan->noisefloor) {
+		s8 delta = chan->noisefloor -
+			   ath9k_hw_get_default_nf(ah, chan);
+		if (delta > 0)
+			noise += delta;
+	}
+	return noise;
 }
 EXPORT_SYMBOL(ath9k_hw_getchan_noise);
 
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1286,6 +1286,7 @@ int ath9k_hw_reset(struct ath_hw *ah, st
 		memset(caldata, 0, sizeof(*caldata));
 		ath9k_init_nfcal_hist_buffer(ah, chan);
 	}
+	ah->noise = ath9k_hw_getchan_noise(ah, chan);
 
 	if (bChannelChange &&
 	    (ah->chip_fullsleep != true) &&
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -677,6 +677,7 @@ struct ath_hw {
 	enum nl80211_iftype opmode;
 	enum ath9k_power_mode power_mode;
 
+	s8 noise;
 	struct ath9k_hw_cal_data *caldata;
 	struct ath9k_pacal_info pacal_info;
 	struct ar5416Stats stats;
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -165,7 +165,7 @@ static void ath_update_survey_nf(struct 
 
 	if (chan->noisefloor) {
 		survey->filled |= SURVEY_INFO_NOISE_DBM;
-		survey->noise = chan->noisefloor;
+		survey->noise = ath9k_hw_getchan_noise(ah, chan);
 	}
 }
 
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -956,6 +956,8 @@ static int ath9k_rx_skb_preprocess(struc
 				   struct ieee80211_rx_status *rx_status,
 				   bool *decrypt_error)
 {
+	struct ath_hw *ah = common->ah;
+
 	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
 
 	/*
@@ -976,7 +978,7 @@ static int ath9k_rx_skb_preprocess(struc
 
 	rx_status->band = hw->conf.channel->band;
 	rx_status->freq = hw->conf.channel->center_freq;
-	rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
+	rx_status->signal = ah->noise + rx_stats->rs_rssi;
 	rx_status->antenna = rx_stats->rs_antenna;
 	rx_status->flag |= RX_FLAG_MACTIME_MPDU;