[PATCH v2] irqchip/bcm2836: Prevent spurious interrupts

[Eric Anholt]

Thomas Gleixner <tglx at linutronix.de> writes:

> On Thu, 27 Oct 2016, Eric Anholt wrote:
>
>> From: Phil Elwell <phil at raspberrypi.org>
>> 
>> 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.
>
> This is missing a fixes tag. I have no idea when that problem was
> introduced, so I have no way to decide whether this needs to be tagged
> stable or not.

This code has been there since introduction of the driver, so:

Fixes: 1a15aaa998dc ("irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2")