svn commit: r210411 - user/adrian/if_ath_devel/sys/dev/ath/ath_hal/ar5416

Adrian Chadd adrian at
Fri Jul 23 12:51:24 UTC 2010

Author: adrian
Date: Fri Jul 23 12:51:23 2010
New Revision: 210411

  Bring over an NF calibration fix from the latest linux wireless-testing ath9k
  The inline comment explains what is going on - on the ar5416 and ar9160
  (at least) writing -50 to the CCA registers during Noise Floor calibration can
  result in the RX side going deaf.
  This has been tested on an SR-71 (AR9160 based) 11n MiniPCI card.
  The initial NF calibration on startup takes longer than the initial
  CCA register loading. It may be possible this occurs during periodic
  Obtained from:	Linux


Modified: user/adrian/if_ath_devel/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c
--- user/adrian/if_ath_devel/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c	Fri Jul 23 12:30:29 2010	(r210410)
+++ user/adrian/if_ath_devel/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c	Fri Jul 23 12:51:23 2010	(r210411)
@@ -552,6 +552,22 @@ ar5416LoadNF(struct ath_hal *ah, const s
+	 * We timed out waiting for the noisefloor to load, probably due to an
+	 * in-progress rx. Simply return here and allow the load plenty of time
+	 * to complete before the next calibration interval.  We need to avoid
+	 * trying to load -50 (which happens below) while the previous load is
+	 * still in progress as this can cause rx deafness. Instead by returning
+	 * here, the baseband nf cal will just be capped by our present
+	 * noisefloor until the next calibration timer.
+	 */
+	if (j == 1000) {
+		HALDEBUG(ah, HAL_DEBUG_ANY, "Timeout while waiting for nf "
+		    "to load: AR_PHY_AGC_CONTROL=0x%x\n",
+		return;
+	}
+	/*
 	 * Restore maxCCAPower register parameter again so that we're not capped
 	 * by the median we just loaded.  This will be initial (and max) value
 	 * of next noise floor calibration the baseband does.  

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