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Commit f41a9b3b authored by Felix Fietkau's avatar Felix Fietkau Committed by John W. Linville
Browse files

ath9k: fix interrupt storms on queued hardware reset 



commit b74713d0
"ath9k: Handle fatal interrupts properly" introduced a race condition, where
IRQs are being left enabled, however the irq handler returns IRQ_HANDLED
while the reset is still queued without addressing the IRQ cause.
This leads to an IRQ storm that prevents the system from even getting to
the reset code.

Fix this by disabling IRQs in the handler without touching intr_ref_cnt.

Cc: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Cc: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: default avatarFelix Fietkau <nbd@openwrt.org>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent bbf2e652

drivers/net/wireless/ath/ath9k/mac.c

+12 −6
Original line number Diff line number Diff line
@@ -773,15 +773,10 @@ bool ath9k_hw_intrpend(struct ath_hw *ah) 
}

EXPORT_SYMBOL(ath9k_hw_intrpend);



void ath9k_hw_disable_interrupts(struct ath_hw *ah)

void ath9k_hw_kill_interrupts(struct ath_hw *ah)

{

	struct ath_common *common = ath9k_hw_common(ah);



	if (!(ah->imask & ATH9K_INT_GLOBAL))

		atomic_set(&ah->intr_ref_cnt, -1);

	else

		atomic_dec(&ah->intr_ref_cnt);



	ath_dbg(common, INTERRUPT, "disable IER\n");

	REG_WRITE(ah, AR_IER, AR_IER_DISABLE);

	(void) REG_READ(ah, AR_IER);
@@ -793,6 +788,17 @@ void ath9k_hw_disable_interrupts(struct ath_hw *ah) 
		(void) REG_READ(ah, AR_INTR_SYNC_ENABLE);

	}

}

EXPORT_SYMBOL(ath9k_hw_kill_interrupts);



void ath9k_hw_disable_interrupts(struct ath_hw *ah)

{

	if (!(ah->imask & ATH9K_INT_GLOBAL))

		atomic_set(&ah->intr_ref_cnt, -1);

	else

		atomic_dec(&ah->intr_ref_cnt);



	ath9k_hw_kill_interrupts(ah);

}

EXPORT_SYMBOL(ath9k_hw_disable_interrupts);



void ath9k_hw_enable_interrupts(struct ath_hw *ah)

drivers/net/wireless/ath/ath9k/mac.h

+1 −0
Original line number Diff line number Diff line
@@ -738,6 +738,7 @@ bool ath9k_hw_intrpend(struct ath_hw *ah); 
void ath9k_hw_set_interrupts(struct ath_hw *ah);

void ath9k_hw_enable_interrupts(struct ath_hw *ah);

void ath9k_hw_disable_interrupts(struct ath_hw *ah);

void ath9k_hw_kill_interrupts(struct ath_hw *ah);



void ar9002_hw_attach_mac_ops(struct ath_hw *ah);

drivers/net/wireless/ath/ath9k/main.c

+3 −1
Original line number Diff line number Diff line
@@ -462,8 +462,10 @@ irqreturn_t ath_isr(int irq, void *dev) 
	if (!ath9k_hw_intrpend(ah))

		return IRQ_NONE;



	if(test_bit(SC_OP_HW_RESET, &sc->sc_flags))

	if (test_bit(SC_OP_HW_RESET, &sc->sc_flags)) {

		ath9k_hw_kill_interrupts(ah);

		return IRQ_HANDLED;

	}



	/*

	 * Figure out the reason(s) for the interrupt.  Note