Re: [PATCH v4 2/2] pinctrl: sunxi: fix gpiochip_lock_as_irq() failure when pinmux is unknown

[Chen-Yu Tsai]

On Fri, Mar 20, 2026 at 12:10 AM Michal Piekos
<michal.piekos@xxxxxxxxxxxxx> wrote:
>
> Fixes kernel hang during boot due to inability to set up IRQ on AXP313a.
>
> The issue is caused by gpiochip_lock_as_irq() which is failing when gpio
> is in unitialized state.

        ^ uninitialized

>
> Solution is to set pinmux to GPIO INPUT in
> sunxi_pinctrl_irq_request_resources() if it wasn't initialized
> earlier.
>
> Tested on Orange Pi Zero 3.
>
> Fixes: 01e10d0272b9 ("pinctrl: sunxi: Implement gpiochip::get_direction()")
> Signed-off-by: Michal Piekos <michal.piekos@xxxxxxxxxxxxx>
> ---
>  drivers/pinctrl/sunxi/pinctrl-sunxi.c | 19 +++++++++++++++++++
>  drivers/pinctrl/sunxi/pinctrl-sunxi.h |  2 ++
>  2 files changed, 21 insertions(+)
>
> diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> index 685b79fc0bf8..321ee97f5745 100644
> --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> @@ -1092,13 +1092,32 @@ static int sunxi_pinctrl_irq_request_resources(struct irq_data *d)
>  {
>         struct sunxi_pinctrl *pctl = irq_data_get_irq_chip_data(d);
>         struct sunxi_desc_function *func;
> +       unsigned int offset;
> +       u32 reg, shift, mask;
> +       u8 muxval;
>         int ret;
> +       bool is_new_layout;
> +       bool is_reset_mux;
>
>         func = sunxi_pinctrl_desc_find_function_by_pin(pctl,
>                                         pctl->irq_array[d->hwirq], "irq");
>         if (!func)
>                 return -EINVAL;
>
> +       offset = pctl->irq_array[d->hwirq] - pctl->desc->pin_base;
> +       sunxi_mux_reg(pctl, offset, &reg, &shift, &mask);
> +       muxval = (readl(pctl->membase + reg) & mask) >> shift;
> +
> +       /* Change muxing to GPIO INPUT mode if at reset value */
> +       is_new_layout = pctl->flags & SUNXI_PINCTRL_NEW_REG_LAYOUT;

You would want

    !!(pctl->flags & SUNXI_PINCTRL_NEW_REG_LAYOUT)

here to normalize it to a bool value. This is quite common in kernel code.

> +       is_reset_mux = (!is_new_layout && muxval == SUN4I_FUNC_DISABLED_OLD) ||
> +                      (is_new_layout && muxval == SUN4I_FUNC_DISABLED_NEW);
> +
> +       if (is_reset_mux) {
> +               sunxi_pmx_set(pctl->pctl_dev, pctl->irq_array[d->hwirq],
> +                             SUN4I_FUNC_INPUT);
> +       }

Nit: the curly braces aren't needed.

> +
>         ret = gpiochip_lock_as_irq(pctl->chip,
>                         pctl->irq_array[d->hwirq] - pctl->desc->pin_base);

Nit: you probably want to replace this with "offset" as well.


Just minor issues, otherwise

Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxxxx>

>         if (ret) {
> diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.h b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
> index 22bffac1c3f0..0daf7600e2fb 100644
> --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.h
> +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
> @@ -86,6 +86,8 @@
>
>  #define SUN4I_FUNC_INPUT       0
>  #define SUN4I_FUNC_IRQ         6
> +#define SUN4I_FUNC_DISABLED_OLD 7
> +#define SUN4I_FUNC_DISABLED_NEW 15
>
>  #define SUNXI_PINCTRL_VARIANT_MASK     GENMASK(7, 0)
>  #define SUNXI_PINCTRL_NEW_REG_LAYOUT   BIT(8)
>
> --
> 2.43.0
>
>