From b5869276205bf8c218672346414aac8adc6e844b Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Fri, 4 Dec 2015 17:41:50 +0000 Subject: [PATCH 006/432] 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(+) diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c index dfe4a460340b..5f881829615c 100644 --- a/drivers/irqchip/irq-bcm2836.c +++ b/drivers/irqchip/irq-bcm2836.c @@ -144,6 +144,7 @@ __exception_irq_entry bcm2836_arm_irqchip_handle_irq(struct pt_regs *regs) u32 ipi = ffs(mbox_val) - 1; writel(1 << ipi, mailbox0); + dsb(sy); handle_IPI(ipi, regs); #endif } else if (stat) { -- 2.19.1