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authorFelix Fietkau <nbd@openwrt.org>2015-01-14 16:17:36 +0300
committerKalle Valo <kvalo@codeaurora.org>2015-01-19 15:32:29 +0300
commite3f31175a3eeb492a6ab788e4fa136c19b43aab4 (patch)
tree2fa9692b9e7a6c1bd78895f09154750480b0452a /drivers/net
parent7b05520160a3252577f9a258609499b73f3bdef1 (diff)
downloadlinux-e3f31175a3eeb492a6ab788e4fa136c19b43aab4.tar.xz
ath9k: fix race condition in irq processing during hardware reset
To fix invalid hardware accesses, the commit 872b5d814f99 ("ath9k: do not access hardware on IRQs during reset") made the irq handler ignore interrupts emitted after queueing a hardware reset (which disables the IRQ). This left a small time window for the IRQ to get re-enabled by the tasklet, which caused IRQ storms. Instead of returning IRQ_NONE when ATH_OP_HW_RESET is set, disable the IRQ entirely for the duration of the reset. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/wireless/ath/ath9k/main.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 9a72640237cb..62b0bf4fdf6b 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -285,6 +285,7 @@ static int ath_reset_internal(struct ath_softc *sc, struct ath9k_channel *hchan)
__ath_cancel_work(sc);
+ disable_irq(sc->irq);
tasklet_disable(&sc->intr_tq);
tasklet_disable(&sc->bcon_tasklet);
spin_lock_bh(&sc->sc_pcu_lock);
@@ -331,6 +332,7 @@ static int ath_reset_internal(struct ath_softc *sc, struct ath9k_channel *hchan)
r = -EIO;
out:
+ enable_irq(sc->irq);
spin_unlock_bh(&sc->sc_pcu_lock);
tasklet_enable(&sc->bcon_tasklet);
tasklet_enable(&sc->intr_tq);
@@ -512,9 +514,6 @@ irqreturn_t ath_isr(int irq, void *dev)
if (!ah || test_bit(ATH_OP_INVALID, &common->op_flags))
return IRQ_NONE;
- if (!AR_SREV_9100(ah) && test_bit(ATH_OP_HW_RESET, &common->op_flags))
- return IRQ_NONE;
-
/* shared irq, not for us */
if (!ath9k_hw_intrpend(ah))
return IRQ_NONE;
@@ -529,7 +528,7 @@ irqreturn_t ath_isr(int irq, void *dev)
ath9k_debug_sync_cause(sc, sync_cause);
status &= ah->imask; /* discard unasked-for bits */
- if (AR_SREV_9100(ah) && test_bit(ATH_OP_HW_RESET, &common->op_flags))
+ if (test_bit(ATH_OP_HW_RESET, &common->op_flags))
return IRQ_HANDLED;
/*