ath9k: serialize ath9k_ps_{wakeup,restore} calls

These functions are changing the power mode of the chip, but this may
have unpredictable effects, if another code are trying to set the power
mode via 'ath9k_hw_setpower' in the same time from another context.

Changes-licensed-under: ISC
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 8b38c0a..1576812 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -576,7 +576,7 @@ struct ath_softc {
        u32 keymax;
        DECLARE_BITMAP(keymap, ATH_KEYMAX);
        u8 splitmic;
-       atomic_t ps_usecount;
+       unsigned long ps_usecount;
        enum ath9k_int imask;
        enum ath9k_ht_extprotspacing ht_extprotspacing;
        enum ath9k_ht_macmode tx_chan_width;

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index df278fd..b9d1a13 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -2777,23 +2777,39 @@ bool ath9k_hw_setpower(struct ath_hw *ah, enum ath9k_power_mode mode)
 
 void ath9k_ps_wakeup(struct ath_softc *sc)
 {
-       if (atomic_inc_return(&sc->ps_usecount) == 1)
-               if (sc->sc_ah->power_mode != ATH9K_PM_AWAKE) {
-                       sc->sc_ah->restore_mode = sc->sc_ah->power_mode;
-                       ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_AWAKE);
-               }
+       unsigned long flags;
+
+       spin_lock_irqsave(&sc->sc_pm_lock, flags);
+       if (++sc->ps_usecount != 1)
+               goto unlock;
+
+       if (sc->sc_ah->power_mode != ATH9K_PM_AWAKE) {
+               sc->sc_ah->restore_mode = sc->sc_ah->power_mode;
+               ath9k_hw_setpower_nolock(sc->sc_ah, ATH9K_PM_AWAKE);
+       }
+
+ unlock:
+       spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
 }
 
 void ath9k_ps_restore(struct ath_softc *sc)
 {
-       if (atomic_dec_and_test(&sc->ps_usecount))
-               if ((sc->hw->conf.flags & IEEE80211_CONF_PS) &&
-                   !(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
-                                     SC_OP_WAIT_FOR_CAB |
-                                     SC_OP_WAIT_FOR_PSPOLL_DATA |
-                                     SC_OP_WAIT_FOR_TX_ACK)))
-                       ath9k_hw_setpower(sc->sc_ah,
-                                         sc->sc_ah->restore_mode);
+       unsigned long flags;
+
+       spin_lock_irqsave(&sc->sc_pm_lock, flags);
+       if (--sc->ps_usecount != 0)
+               goto unlock;
+
+       if ((sc->hw->conf.flags & IEEE80211_CONF_PS) &&
+               !(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
+                               SC_OP_WAIT_FOR_CAB |
+                               SC_OP_WAIT_FOR_PSPOLL_DATA |
+                               SC_OP_WAIT_FOR_TX_ACK)))
+               ath9k_hw_setpower_nolock(sc->sc_ah,
+                                     sc->sc_ah->restore_mode);
+
+ unlock:
+       spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
 }
 
 /*