[RFC] ath9k: fix race conditions when stop device

Commit Message

Stanislaw Gruszka Jan. 21, 2011, 6:06 a.m. UTC

None

Patch

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 767d8b8..b3254a3 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -598,8 +598,6 @@  err_btcoex:
 err_queues:
 	ath9k_hw_deinit(ah);
 err_hw:
-	tasklet_kill(&sc->intr_tq);
-	tasklet_kill(&sc->bcon_tasklet);
 
 	kfree(ah);
 	sc->sc_ah = NULL;
@@ -807,9 +805,6 @@  static void ath9k_deinit_softc(struct ath_softc *sc)
 
 	ath9k_hw_deinit(sc->sc_ah);
 
-	tasklet_kill(&sc->intr_tq);
-	tasklet_kill(&sc->bcon_tasklet);
-
 	kfree(sc->sc_ah);
 	sc->sc_ah = NULL;
 }
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index c03184e..42cfd96 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1320,6 +1320,9 @@  static void ath9k_stop(struct ieee80211_hw *hw)
 
 	spin_lock_bh(&sc->sc_pcu_lock);
 
+	/* prevent tasklets to enable interrupts once we disable them */
+	ah->imask &= ~ATH9K_INT_GLOBAL;
+
 	/* make sure h/w will not generate any interrupt
 	 * before setting the invalid flag. */
 	ath9k_hw_disable_interrupts(ah);
@@ -1337,6 +1340,12 @@  static void ath9k_stop(struct ieee80211_hw *hw)
 
 	spin_unlock_bh(&sc->sc_pcu_lock);
 
+	/* we can now sync irq and kill any running tasklets, since we already
+	 * disabled interrupts and not holding a spin lock */
+	synchronize_irq(sc->irq);
+	tasklet_kill(&sc->intr_tq);
+	tasklet_kill(&sc->bcon_tasklet);
+
 	ath9k_ps_restore(sc);
 
 	sc->ps_idle = true;