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			54 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			54 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From: Felix Fietkau <nbd@openwrt.org>
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Date: Wed, 14 Jan 2015 14:13:15 +0100
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Subject: [PATCH] ath9k: fix race condition in irq processing during hardware
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 reset
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To fix invalid hardware accesses, the commit
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"ath9k: do not access hardware on IRQs during reset" made the irq
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handler ignore interrupts emitted after queueing a hardware reset (which
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disables the IRQ). This left a small time window for the IRQ to get
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re-enabled by the tasklet, which caused IRQ storms.
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Instead of returning IRQ_NONE when ATH_OP_HW_RESET is set, disable the
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IRQ entirely for the duration of the reset.
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Signed-off-by: Felix Fietkau <nbd@openwrt.org>
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---
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--- a/drivers/net/wireless/ath/ath9k/main.c
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+++ b/drivers/net/wireless/ath/ath9k/main.c
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@@ -285,6 +285,7 @@ static int ath_reset_internal(struct ath
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 	__ath_cancel_work(sc);
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+	disable_irq(sc->irq);
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 	tasklet_disable(&sc->intr_tq);
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 	tasklet_disable(&sc->bcon_tasklet);
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 	spin_lock_bh(&sc->sc_pcu_lock);
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@@ -331,6 +332,7 @@ static int ath_reset_internal(struct ath
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 		r = -EIO;
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 out:
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+	enable_irq(sc->irq);
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 	spin_unlock_bh(&sc->sc_pcu_lock);
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 	tasklet_enable(&sc->bcon_tasklet);
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 	tasklet_enable(&sc->intr_tq);
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@@ -512,9 +514,6 @@ irqreturn_t ath_isr(int irq, void *dev)
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 	if (!ah || test_bit(ATH_OP_INVALID, &common->op_flags))
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 		return IRQ_NONE;
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-	if (!AR_SREV_9100(ah) && test_bit(ATH_OP_HW_RESET, &common->op_flags))
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-		return IRQ_NONE;
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-
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 	/* shared irq, not for us */
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 	if (!ath9k_hw_intrpend(ah))
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 		return IRQ_NONE;
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@@ -529,7 +528,7 @@ irqreturn_t ath_isr(int irq, void *dev)
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 	ath9k_debug_sync_cause(sc, sync_cause);
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 	status &= ah->imask;	/* discard unasked-for bits */
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-	if (AR_SREV_9100(ah) && test_bit(ATH_OP_HW_RESET, &common->op_flags))
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+	if (test_bit(ATH_OP_HW_RESET, &common->op_flags))
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 		return IRQ_HANDLED;
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 	/*
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