Re: [PATCH] pinctrl/amd: poll InterruptEnable bits in enable_irq

From: Linus Walleij
Date: Mon Mar 26 2018 - 05:12:33 EST


On Mon, Mar 12, 2018 at 5:45 PM, Daniel Kurtz <djkurtz@xxxxxxxxxxxx> wrote:

> In certain cases interrupt enablement will be delayed relative to when
> the InterruptEnable bits are written. One example of this is when
> a GPIO's "debounce" logice is first enabled. After enabling debounce,
> there is a 900 us "warm up" period during which InterruptEnable[0]
> (bit 11) will read as 0 despite being written 1. During this time
> InterruptSts will not be updated, nor will interrupts be delivered, even
> if the GPIO's interrupt configuration has been written to the register.
>
> To work around this delay, poll the InterruptEnable bits after setting
> them to ensure interrupts have truly been enabled in hardware before
> returning from the irq_enable handler.
>
> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>

Patch applied.

I see the AMD people were not on CC so adding them here so they can
say if there is any problem with the approach.

Daniel: maybe you should consider listing yourself as comaintainer of this
driver?

Yours,
Linus Walleij