Re: [PATCH] pinctrl: spacemit: fix NULL check in spacemit_pin_set_config

[Linus Walleij]

On Tue, May 19, 2026 at 6:40 PM Han Gao <gaohan@xxxxxxxxxxx> wrote:

> spacemit_pin_set_config() looks up the per-pin descriptor with
> spacemit_get_pin() then checks the wrong variable for failure:
>
>         const struct spacemit_pin *spin = spacemit_get_pin(pctrl, pin);
>         ...
>         if (!pin)
>                 return -EINVAL;
>
>         reg = spacemit_pin_to_reg(pctrl, spin->pin);
>
> pin is an unsigned int pin id, where 0 (GPIO_0 / gmac0_rxdv on K3) is a
> valid pin, so rejecting it here drops the PAD config write for the first
> pin of every group. On K3 Pico-ITX the GMAC RGMII group lists pin 0 as
> its first entry, so its drive-strength / bias configuration was silently
> ignored.
>
> The intended guard is against spacemit_get_pin() returning NULL when the
> pin id isn't in the SoC's pin table. Check spin instead, which both
> restores PAD setup for pin 0 and prevents a NULL deref on spin->pin.
>
> Fixes: a83c29e1d145 ("pinctrl: spacemit: add support for SpacemiT K1 SoC")
> Signed-off-by: Han Gao <gaohan@xxxxxxxxxxx>

Patch applied for noncritical fixes.

Yours,
Linus Walleij