From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 18 Oct 2014 13:39:11 +0200
Subject: [PATCH] ath9k_hw: do not run NF and periodic calibration at the
 same time

It can cause inconsistent calibration results or in some cases turn the
radio deaf.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---

--- a/drivers/net/wireless/ath/ath9k/ar9002_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9002_calib.c
@@ -660,27 +660,26 @@ static void ar9002_hw_olc_temp_compensat
 static int ar9002_hw_calibrate(struct ath_hw *ah, struct ath9k_channel *chan,
 			       u8 rxchainmask, bool longcal)
 {
-	bool iscaldone = true;
 	struct ath9k_cal_list *currCal = ah->cal_list_curr;
-	bool nfcal, nfcal_pending = false;
+	bool nfcal, nfcal_pending = false, percal_pending;
 	int ret;
 
 	nfcal = !!(REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF);
 	if (ah->caldata)
 		nfcal_pending = test_bit(NFCAL_PENDING, &ah->caldata->cal_flags);
 
-	if (currCal && !nfcal &&
-	    (currCal->calState == CAL_RUNNING ||
-	     currCal->calState == CAL_WAITING)) {
-		iscaldone = ar9002_hw_per_calibration(ah, chan,
-						      rxchainmask, currCal);
-		if (iscaldone) {
-			ah->cal_list_curr = currCal = currCal->calNext;
-
-			if (currCal->calState == CAL_WAITING) {
-				iscaldone = false;
-				ath9k_hw_reset_calibration(ah, currCal);
-			}
+	percal_pending = (currCal &&
+			  (currCal->calState == CAL_RUNNING ||
+			   currCal->calState == CAL_WAITING));
+
+	if (percal_pending && !nfcal) {
+		if (!ar9002_hw_per_calibration(ah, chan, rxchainmask, currCal))
+			return 0;
+
+		ah->cal_list_curr = currCal = currCal->calNext;
+		if (currCal->calState == CAL_WAITING) {
+			ath9k_hw_reset_calibration(ah, currCal);
+			return 0;
 		}
 	}
 
@@ -710,7 +709,7 @@ static int ar9002_hw_calibrate(struct at
 		}
 	}
 
-	return iscaldone;
+	return !percal_pending;
 }
 
 /* Carrier leakage Calibration fix */