[PATCH] pinctrl: bcm2835: Clear the event latch register when disabling interrupts

[Stephen Warren]

On 06/30/2015 05:35 AM, Jonathan Bell wrote:
> It's possible to hit a race condition if interrupts are generated on a GPIO
> pin when the IRQ line in question is being disabled.
> 
> If the interrupt is freed, bcm2835_gpio_irq_disable() is called which
> disables the event generation sources (edge, level). If an event occurred
> between the last disabling of hard IRQs and the write to the event
> source registers, a bit would be set in the GPIO event detect register
> (GPEDSn) which goes unacknowledged by bcm2835_gpio_irq_handler()
> so Linux complains loudly.
> 
> There is no per-GPIO mask register, so when disabling GPIO interrupts
> write 1 to the relevant bit in GPEDSn to clear out any stale events.

Acked-by: Stephen Warren <swarren at wwwdotorg.org>

(Sorry for the slow response; I was on vacation)