Re: [PATCH] x86/irq: Do not touch IRQ chip_data if it does not belong to x86_vector_domain

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Mika,

On 10/03/16 13:17, Mika Westerberg wrote:
> When a CPU is about to be offlined we call fixup_irqs() that resets IRQ
> affinities related to the CPU in question. The same thing is also done when
> the system is suspended to S-states like S3 (mem).
> 
> For each IRQ we try to complete any on-going move regardless whether the
> IRQ is actually part of x86_vector_domain. For each IRQ descriptor we fetch
> its chip_data, assume it is of type struct apic_chip_data and manipulate it
> by clearing old_domain mask etc. For irq_chips that are not part of the
> x86_vector_domain, like those created by various GPIO drivers, will find
> their chip_data being changed unexpectly.
> 
> Below is an example where GPIO chip owned by pinctrl-sunrisepoint.c gets
> corrupted after resume:
> 
>   # cat /sys/kernel/debug/gpio
>   gpiochip0: GPIOs 360-511, parent: platform/INT344B:00, INT344B:00:
>    gpio-511 (                    |sysfs               ) in  hi
> 
>   # rtcwake -s10 -mmem
>   <10 seconds passes>
> 
>   # cat /sys/kernel/debug/gpio
>   gpiochip0: GPIOs 360-511, parent: platform/INT344B:00, INT344B:00:
>    gpio-511 (                    |sysfs               ) in  ?
> 
> Note '?' in the output. It means the struct gpio_chip ->get function is
> NULL whereas before suspend it was there.
> 
> Fix this by first checking that the IRQ belongs to x86_vector_domain before
> we try to use the chip_data as struct apic_chip_data.
> 
> Reported-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Thanks for debugging this! I've tested it on the laptop where the SD
card is no longer detected after suspend; with this patch it works fine.

Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Sakari Ailus
sakari.ailus@linux.intel.com