Re: [PATCH v1] gpiolib: Handle no pin_ranges in gpiochip_generic_config()

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Mon, Feb 19, 2024 at 6:25 PM Emil Renner Berthing
<emil.renner.berthing@xxxxxxxxxxxxx> wrote:

> Similar to gpiochip_generic_request() and gpiochip_generic_free() the
> gpiochip_generic_config() function needs to handle the case where there
> are no pinctrl pins mapped to the GPIOs, usually through the gpio-ranges
> device tree property.
>
> Commit f34fd6ee1be8 ("gpio: dwapb: Use generic request, free and
> set_config") set the .set_config callback to gpiochip_generic_config()
> in the dwapb GPIO driver so the GPIO API can set pinctrl configuration
> for the corresponding pins. Most boards using the dwapb driver do not
> set the gpio-ranges device tree property though, and in this case
> gpiochip_generic_config() would return -EPROPE_DEFER rather than the
> previous -ENOTSUPP return value. This in turn makes
> gpio_set_config_with_argument_optional() fail and propagate the error to
> any driver requesting GPIOs.
>
> Fixes: 2956b5d94a76 ("pinctrl / gpio: Introduce .set_config() callback for GPIO chips")
> Reported-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-gpio/ZdC_g3U4l0CJIWzh@xhacker/
> Tested-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> Signed-off-by: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>

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

> I didn't add your rb since I don't think
>   if (IS_ENABLED(CONFIG_PINCTRL) && list_empty(&gc->gpiodev->pin_ranges))
> will work when the pin_ranges member is only there then when
> CONFIG_PINCTRL is defined and it seemed like your rb was on the
> condition that I used that.

I was wrong about that!

Yours,
Linus Walleij