ath9k: fix crashes when using shared IRQs

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 43239

1 files changed, 51 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/311-ath9k-do-not-access-hardware-on-IRQs-during-reset.patch b/package/kernel/mac80211/patches/311-ath9k-do-not-access-hardware-on-IRQs-during-reset.patch
new file mode 100644
index 0000000000..7996725025
--- /dev/null
+++ b/package/kernel/mac80211/patches/311-ath9k-do-not-access-hardware-on-IRQs-during-reset.patch
@@ -0,0 +1,51 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Thu, 13 Nov 2014 18:29:26 +0100
+Subject: [PATCH] ath9k: do not access hardware on IRQs during reset
+
+Instead of killing interrupts during reset when the first one happens,
+kill them before issuing the reset.
+This fixes an easy to reproduce crash with multiple cards sharing the
+same IRQ.
+
+Cc: stable@vger.kernel.org
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -512,16 +512,13 @@ irqreturn_t ath_isr(int irq, void *dev)
+ 	if (!ah || test_bit(ATH_OP_INVALID, &common->op_flags))
+ 		return IRQ_NONE;
+ 
+-	/* shared irq, not for us */
++	if (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;
+ 
+-	if (test_bit(ATH_OP_HW_RESET, &common->op_flags)) {
+-		ath9k_hw_kill_interrupts(ah);
+-		return IRQ_HANDLED;
+-	}
+-
+ 	/*
+ 	 * Figure out the reason(s) for the interrupt.  Note
+ 	 * that the hal returns a pseudo-ISR that may include
+@@ -613,6 +610,7 @@ int ath_reset(struct ath_softc *sc, stru
+ 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+ 	int r;
+ 
++	ath9k_hw_kill_interrupts(sc->sc_ah);
+ 	set_bit(ATH_OP_HW_RESET, &common->op_flags);
+ 
+ 	ath9k_ps_wakeup(sc);
+@@ -633,6 +631,7 @@ void ath9k_queue_reset(struct ath_softc 
+ #ifdef CPTCFG_ATH9K_DEBUGFS
+ 	RESET_STAT_INC(sc, type);
+ #endif
++	ath9k_hw_kill_interrupts(sc->sc_ah);
+ 	set_bit(ATH_OP_HW_RESET, &common->op_flags);
+ 	ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+ }