Re: [PATCH] gpio: Request interrupts after IRQ is initialized

[Linus Walleij]

On Thu, Apr 14, 2022 at 4:57 AM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:

> commit 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before
> initialization") attempted to fix a race condition that lead to a NULL
> pointer, but in the process caused a regression for _AEI/_EVT declared
> GPIOs. This manifests in messages showing deferred probing while trying
> to allocate IRQs like so:
>
> [    0.688318] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0000 to IRQ, err -517
> [    0.688337] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x002C to IRQ, err -517
> [    0.688348] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003D to IRQ, err -517
> [    0.688359] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003E to IRQ, err -517
> [    0.688369] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003A to IRQ, err -517
> [    0.688379] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003B to IRQ, err -517
> [    0.688389] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0002 to IRQ, err -517
> [    0.688399] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0011 to IRQ, err -517
> [    0.688410] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0012 to IRQ, err -517
> [    0.688420] amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0007 to IRQ, err -517
>
> The code for walking _AEI doesn't handle deferred probing and so this leads
> to non-functional GPIO interrupts.
>
> Fix this issue by moving the call to `acpi_gpiochip_request_interrupts` to
> occur after gc->irc.initialized is set.
>
> Cc: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
> Reported-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Link: https://lore.kernel.org/linux-gpio/BL1PR12MB51577A77F000A008AA694675E2EF9@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#u
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>

Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij