svn commit: r225421 - head/sys/dev/ath/ath_hal/ar5416

[Adrian Chadd]

Author: adrian
Date: Tue Sep  6 10:54:56 2011
New Revision: 225421
URL: http://svn.freebsd.org/changeset/base/225421

Log:
  Fix 5ghz calibration logic when using AR9280 w/ fast clock.
  
  When the fast clock (44mhz) is enabled for 5ghz HT20, the
  dual ADCs aren't enabled. Trying to do the ADC calibrations
  here would result in calibration never completing; this
  resulted in IQ calibration never running and thus performance
  issues in 11a/11n HT20 mode.
  
  Leave it enabled for non-fastclock (40mhz) 11a mode and
  HT40 modes.
  
  This has been fixed in discussion with Felix Fietkau (nbd)
  and discussions with the Atheros baseband team.
  
  Linux ath9k now has a similar fix.
  
  Approved by:	re (kib)

Modified:
  head/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c

Modified: head/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c
==============================================================================
--- head/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c	Tue Sep  6 10:49:05 2011	(r225420)
+++ head/sys/dev/ath/ath_hal/ar5416/ar5416_cal.c	Tue Sep  6 10:54:56 2011	(r225421)
@@ -72,16 +72,17 @@ ar5416IsCalSupp(struct ath_hal *ah, cons
 		return !IEEE80211_IS_CHAN_B(chan);
 	case ADC_GAIN_CAL:
 	case ADC_DC_CAL:
-		/* Run ADC Gain Cal for either 5ghz any or 2ghz HT40 */
 		/*
-		 * Merlin (AR9280) doesn't ever complete ADC calibrations
-		 * in 5ghz non-HT40 mode (ie, HT20, 11a). For now, disable
-		 * it for Merlin only until further information is
-		 * available.
+		 * Run ADC Gain Cal for either 5ghz any or 2ghz HT40.
+		 *
+		 * Don't run ADC calibrations for 5ghz fast clock mode
+		 * in HT20 - only one ADC is used.
 		 */
-		if (! AR_SREV_MERLIN(ah))
-			if (IEEE80211_IS_CHAN_5GHZ(chan))
-				return AH_TRUE;
+		if (IEEE80211_IS_CHAN_HT20(chan) &&
+		    (IS_5GHZ_FAST_CLOCK_EN(ah, chan)))
+			return AH_FALSE;
+		if (IEEE80211_IS_CHAN_5GHZ(chan))
+			return AH_TRUE;
 		if (IEEE80211_IS_CHAN_HT40(chan))
 			return AH_TRUE;
 		return AH_FALSE;