From: Felix Fietkau Date: Wed, 14 Jan 2015 13:17:36 +0000 (+0100) Subject: ath9k: fix race condition in irq processing during hardware reset X-Git-Tag: firefly_0821_release~176^2~2456^2~25^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e3f31175a3eeb492a6ab788e4fa136c19b43aab4;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Kalle Valo --- 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; /*