ath9k: fix channel time updates when the interface is idle

SVN-Revision: 23410

package/mac80211/patches/527-ath9k_ps_survey_fix.patch

@@ -0,0 +1,54 @@
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -122,6 +122,7 @@ bool ath9k_setpower(struct ath_softc *sc
+ 
+ void ath9k_ps_wakeup(struct ath_softc *sc)
+ {
++	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+ 	unsigned long flags;
+ 
+ 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
+@@ -130,18 +131,33 @@ void ath9k_ps_wakeup(struct ath_softc *s
+ 
+ 	ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_AWAKE);
+ 
++	/*
++	 * While the hardware is asleep, the cycle counters contain no
++	 * useful data. Better clear them now so that they don't mess up the
++	 * ANI or survey data results.
++	 */
++	spin_lock(&common->cc_lock);
++	ath_hw_cycle_counters_update(common);
++	memset(&common->cc_survey, 0, sizeof(common->cc_survey));
++	spin_unlock(&common->cc_lock);
++
+  unlock:
+ 	spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+ }
+ 
+ void ath9k_ps_restore(struct ath_softc *sc)
+ {
++	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+ 	unsigned long flags;
+ 
+ 	spin_lock_irqsave(&sc->sc_pm_lock, flags);
+ 	if (--sc->ps_usecount != 0)
+ 		goto unlock;
+ 
++	spin_lock(&common->cc_lock);
++	ath_hw_cycle_counters_update(common);
++	spin_unlock(&common->cc_lock);
++
+ 	if (sc->ps_idle)
+ 		ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_FULL_SLEEP);
+ 	else if (sc->ps_enabled &&
+@@ -197,7 +213,8 @@ static void ath_update_survey_stats(stru
+ 	struct ath_cycle_counters *cc = &common->cc_survey;
+ 	unsigned int div = common->clockrate * 1000;
+ 
+-	ath_hw_cycle_counters_update(common);
++	if (ah->power_mode == ATH9K_PM_AWAKE)
++		ath_hw_cycle_counters_update(common);
+ 
+ 	if (cc->cycles > 0) {
+ 		survey->filled |= SURVEY_INFO_CHANNEL_TIME |