From 71069bc740f638495eb33d6db6a281b5fa697657 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(+) diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c index d96b2c947e74..93e3f7660c42 100644 --- a/drivers/irqchip/irq-bcm2836.c +++ b/drivers/irqchip/irq-bcm2836.c @@ -175,6 +175,7 @@ __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) { -- 2.30.2