Re: [PATCH] pinctrl/amd: disable spurious-firing GPIO IRQs

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Wed, Aug 14, 2019 at 11:05 AM Daniel Drake <drake@xxxxxxxxxxxx> wrote:

> When cold-booting Asus X434DA, GPIO 7 is found to be already configured
> as an interrupt, and the GPIO level is found to be in a state that
> causes the interrupt to fire.
>
> As soon as pinctrl-amd probes, this interrupt fires and invokes
> amd_gpio_irq_handler(). The IRQ is acked, but no GPIO-IRQ handler was
> invoked, so the GPIO level being unchanged just causes another interrupt
> to fire again immediately after.
>
> This results in an interrupt storm causing this platform to hang
> during boot, right after pinctrl-amd is probed.
>
> Detect this situation and disable the GPIO interrupt when this happens.
> This enables the affected platform to boot as normal. GPIO 7 actually is
> the I2C touchpad interrupt line, and later on, i2c-multitouch loads and
> re-enables this interrupt when it is ready to handle it.
>
> Instead of this approach, I considered disabling all GPIO interrupts at
> probe time, however that seems a little risky, and I also confirmed that
> Windows does not seem to have this behaviour: the same 41 GPIO IRQs are
> enabled under both Linux and Windows, which is a far larger collection
> than the GPIOs referenced by the DSDT on this platform.
>
> Signed-off-by: Daniel Drake <drake@xxxxxxxxxxxx>

Patch applied!

Yours,
Linus Walleij