Re: commit f34fd6ee1be8 breaks current dwapb gpio DT users

[Jisheng Zhang <jszhang@kernel.org>]

On Sat, Feb 17, 2024 at 09:44:27AM -0800, Emil Renner Berthing wrote:
> Jisheng Zhang wrote:
> > Hi Emil, Linus,
> >
> > commit f34fd6ee1be8 ("gpio: dwapb: Use generic request, free and
> > set_config") breaks all current dwapb gpio DT users, for example, getting
> > cd-gpios will always fail as -EPROBE_DEFER. Before the commit,
> > dwapb_gpio_set_config() returns -ENOTSUPP for !PIN_CONFIG_INPUT_DEBOUNCE
> > then gpio_set_config_with_argument_optional() will happily ignore
> > -ENOTSUPP. After the commit, dwapb_gpio_set_config() will return
> > -EPROBE_DEFER unless the gpio-ranges are set in DT.
> >
> > The key problem here is: almost all dwapb gpio DT users don't set
> > the gpio-ranges DT property, so I guess current dwapb gpio DT users
> > have this problem and the commit also breaks old DT compatbility.
> > So could we getback to previous behavior?
> 
> Hi Jisheng
> 
> It seems like the gpiochip_generic_request() and gpiochip_generic_free()
> functions have guards to handle when gpio-ranges are not set that
> gpiochip_generic_config() lacks. Could you try the patch below?
> 
> Otherwise I'm also fine with just reverting the patch if this is not the right
> solution.
> 
> /Emil
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 8b3a0f45b574..e434e8cc1229 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -2042,6 +2042,11 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_free);
>  int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
>                             unsigned long config)
>  {
> +#ifdef CONFIG_PINCTRL
> +       if (list_empty(&gc->gpiodev->pin_ranges))
> +               return -ENOTSUPP;
> +#endif
> +
>         return pinctrl_gpio_set_config(gc, offset, config);
>  }
>  EXPORT_SYMBOL_GPL(gpiochip_generic_config);

Hi Emil,

The above patch can fix the gpio issue. So,
Reported-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Jisheng Zhang <jszhang@kernel.org>

Thanks