From a570ccd7e25ff66ba61753ef2363ecbcd99f1b7b Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Wed, 14 Jan 2015 13:20:38 +0000 Subject: ath9k: fix irq storm issues (#18483) Signed-off-by: Felix Fietkau SVN-Revision: 43971 --- ...ace-condition-in-irq-processing-during-ha.patch | 53 ++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 package/kernel/mac80211/patches/329-ath9k-fix-race-condition-in-irq-processing-during-ha.patch (limited to 'package/kernel/mac80211/patches/329-ath9k-fix-race-condition-in-irq-processing-during-ha.patch') diff --git a/package/kernel/mac80211/patches/329-ath9k-fix-race-condition-in-irq-processing-during-ha.patch b/package/kernel/mac80211/patches/329-ath9k-fix-race-condition-in-irq-processing-during-ha.patch new file mode 100644 index 0000000000..69b21e7284 --- /dev/null +++ b/package/kernel/mac80211/patches/329-ath9k-fix-race-condition-in-irq-processing-during-ha.patch @@ -0,0 +1,53 @@ +From: Felix Fietkau +Date: Wed, 14 Jan 2015 14:13:15 +0100 +Subject: [PATCH] ath9k: fix race condition in irq processing during hardware + reset + +To fix invalid hardware accesses, the commit +"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 +--- + +--- 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 + + __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 + 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; + + /* -- cgit v1.2.3