ath9k: add noise floor parameter to ath9k_hw_getchan_noise

Add nf parameter to ath9k_hw_getchan_noise() in order to compute NF for EXT
chains with the same scale of noise floor calculated on CTL chains.
ath9k_hw_getchan_noise() will be used in ath_process_fft() for spectral scan on
HT40 channels

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/calib.c b/drivers/net/wireless/ath/ath9k/calib.c
index d8db74b..278365b 100644
--- a/drivers/net/wireless/ath/ath9k/calib.c
+++ b/drivers/net/wireless/ath/ath9k/calib.c
@@ -63,13 +63,13 @@
 	return ath9k_hw_get_nf_limits(ah, chan)->nominal;
 }
 
-s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan)
+s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan,
+			   s16 nf)
 {
 	s8 noise = ATH_DEFAULT_NOISE_FLOOR;
 
-	if (chan && chan->noisefloor) {
-		s8 delta = chan->noisefloor -
-			   ATH9K_NF_CAL_NOISE_THRESH -
+	if (nf) {
+		s8 delta = nf - ATH9K_NF_CAL_NOISE_THRESH -
 			   ath9k_hw_get_default_nf(ah, chan);
 		if (delta > 0)
 			noise += delta;
@@ -392,7 +392,7 @@
 	clear_bit(NFCAL_PENDING, &caldata->cal_flags);
 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
 	chan->noisefloor = h[0].privNF;
-	ah->noise = ath9k_hw_getchan_noise(ah, chan);
+	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
 	return true;
 }
 EXPORT_SYMBOL(ath9k_hw_getnf);
diff --git a/drivers/net/wireless/ath/ath9k/calib.h b/drivers/net/wireless/ath/ath9k/calib.h
index 3d70b8c..b8ed95e 100644
--- a/drivers/net/wireless/ath/ath9k/calib.h
+++ b/drivers/net/wireless/ath/ath9k/calib.h
@@ -116,7 +116,8 @@
 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah);
 void ath9k_hw_reset_calibration(struct ath_hw *ah,
 				struct ath9k_cal_list *currCal);
-s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan);
+s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan,
+			   s16 nf);
 
 
 #endif /* CALIB_H */
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index dcdbab4..54b0415 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1885,7 +1885,7 @@
 	} else if (caldata) {
 		clear_bit(PAPRD_PACKET_SENT, &caldata->cal_flags);
 	}
-	ah->noise = ath9k_hw_getchan_noise(ah, chan);
+	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
 
 	if (fastcc) {
 		r = ath9k_hw_do_fastcc(ah, chan);
diff --git a/drivers/net/wireless/ath/ath9k/link.c b/drivers/net/wireless/ath/ath9k/link.c
index 84a6064..b797519 100644
--- a/drivers/net/wireless/ath/ath9k/link.c
+++ b/drivers/net/wireless/ath/ath9k/link.c
@@ -518,7 +518,8 @@
 
 	if (chan->noisefloor) {
 		survey->filled |= SURVEY_INFO_NOISE_DBM;
-		survey->noise = ath9k_hw_getchan_noise(ah, chan);
+		survey->noise = ath9k_hw_getchan_noise(ah, chan,
+						       chan->noisefloor);
 	}
 }