From 0badcb291f4fb5c3477c37b4ad4a0e27dd863272 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Fri, 4 Dec 2015 17:41:50 +0000 Subject: [PATCH] irq-bcm2836: Prevent spurious interrupts, and trap them early The old arch-specific IRQ macros included a dsb to ensure the write to clear the mailbox interrupt completed before returning from the interrupt. The BCM2836 irqchip driver needs the same precaution to avoid spurious interrupts. Spurious interrupts are still possible for other reasons, though, so trap them early. --- drivers/irqchip/irq-bcm2836.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/irqchip/irq-bcm2836.c +++ b/drivers/irqchip/irq-bcm2836.c @@ -175,6 +175,7 @@ __exception_irq_entry bcm2836_arm_irqchi u32 ipi = ffs(mbox_val) - 1; writel(1 << ipi, mailbox0); + dsb(sy); handle_IPI(ipi, regs); #endif } else if (stat) {