Re: [PATCH v2] pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Wed, May 4, 2016 at 10:21 AM, Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> wrote:

> Currrently the gpio_chip.to_irq() callback returns -ENOSYS on error,
> which causes bad interactions with the serial_mctrl_gpio helpers.
>
> mctrl_gpio_init() returns -ENOSYS if GPIOLIB is not enabled, which is
> intended to be ignored by its callers. However, ignoring -ENOSYS when it
> was caused by a gpiod_to_irq() failure will lead to a crash later:
>
>     Unable to handle kernel paging request at virtual address ffffffde
>     ...
>     PC is at mctrl_gpio_set+0x14/0x78
>
> Fix this by returning zero instead, like gpiochip_to_irq() does.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> This depends on "gpio: make gpiod_to_irq() return negative for NO_IRQ"
> for proper handling by callers of mctrl_gpio_init().
> Hence I think it's best to take this through the GPIO tree, after the
> above has been applied.
>
> v2:
>   - Return zero instead of -ENXIO.

Patch applied.

Yours,
Linus Walleij
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