Re: [RFC PATCH 1/3] dt-bindings: pinctrl: mt8516/mt8167: Move compatibles from mt66xx to mt6795

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Critical] The patch series permanently breaks Device Tree backward compatibility (ABI breakage). By moving the mt8167 and mt8516 SoCs to the mt6795 bindings and pinctrl-paris.c driver, the schema now unconditionally requires `reg-names` and `gpio-ranges` and forbids the legacy `mediatek,pctl-regmap` layout. Furthermore, the updated driver calls `devm_platform_ioremap_resource_byname(pdev, "base")` and fails with `-EINVAL` if `reg-names` is absent. Booting a new kernel with an older, previously valid device tree will fail to probe the pinctrl driver, breaking all GPIO-dependent devices.
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commit ae4fde26bd3f120a43beccf98009171f05144eee
Author: Luca Leonardo Scorcia <l.scorcia@gmail.com>

dt-bindings: pinctrl: mt8516/mt8167: Move compatibles from mt66xx to mt6795

Pinctrl settings for MediaTek mt8516-mt8167 SoCs use two reg base
addresses, one for GPIO and the other for EINT, as it is common in the
"Paris" pinctrl platform. This commit moves the mediatek,mt8516-pinctrl and
mediatek,mt8167-pinctrl compatible strings to the mt6795-pinctrl binding.

[ ... ]

> diff --git a/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml
> index 9a937f414cc98..c703de72e1d52 100644
> --- a/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml
> +++ b/Documentation/devicetree/bindings/pinctrl/mediatek,mt6795-pinctrl.yaml
> @@ -15,7 +15,10 @@ description:
>  
>  properties:
>    compatible:
> -    const: mediatek,mt6795-pinctrl
> +    enum:
> +      - mediatek,mt6795-pinctrl
> +      - mediatek,mt8167-pinctrl
> +      - mediatek,mt8516-pinctrl

[Severity: Critical]
Does moving these compatibles to this binding break Device Tree backward
compatibility?

The schema now unconditionally requires properties like reg-names and
gpio-ranges, and forbids the legacy mediatek,pctl-regmap layout without an
allOf: if-then conditional to accommodate older hardware descriptions.

Furthermore, the updated driver unconditionally requires the reg-names
property:

drivers/pinctrl/mediatek/pinctrl-paris.c:mtk_paris_pinctrl_probe() {
    ...
		hw->base[i] = devm_platform_ioremap_resource_byname(pdev,
					hw->soc->base_names[i]);
    ...
}

Because older device trees lack the reg-names property, this call returns
-EINVAL and fails the probe.

Will booting a new kernel with an older device tree fail to probe the
pinctrl driver, breaking all GPIO-dependent peripherals?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260625104742.113803-1-l.scorcia@gmail.com?part=1