ath9k: do not track cycle counter updates in powersave mode
authorFelix Fietkau <nbd@openwrt.org>
Tue, 12 Oct 2010 12:02:53 +0000 (14:02 +0200)
committerJohn W. Linville <linville@tuxdriver.com>
Fri, 15 Oct 2010 19:48:44 +0000 (15:48 -0400)
While the chip is in powersave mode, the cycle counter updates do not
contain useful values. While the chip is in full sleep, the rx_clear
signal stays high, indicating a busy medium.
To ensure sane values, update cycle counters before going into
powersave, and clear them right after switching back to awake.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/ath/ath9k/main.c

index bcd3892dca8d1aca390807d7ec73435d27f14857..74ff51d4c339b3fa8f5c39cd60343447e872b660 100644 (file)
@@ -121,6 +121,7 @@ bool ath9k_setpower(struct ath_softc *sc, enum ath9k_power_mode mode)
 
 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);
@@ -129,18 +130,33 @@ void ath9k_ps_wakeup(struct ath_softc *sc)
 
        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
+        * 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 &&
@@ -196,7 +212,8 @@ static void ath_update_survey_stats(struct ath_softc *sc)
        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 |