Re: [PATCH v14 02/23] dt-bindings: ufs: mediatek,ufs: Complete the binding

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dt-bindings: ufs: mediatek: incompatible schema change breaks in-tree mt8195.dtsi
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commit 2eee1dd0c91a095faf6d7717e0d6ad307cbf851d
Author: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

dt-bindings: ufs: mediatek,ufs: Complete the binding

This commit updates the mediatek,ufs.yaml binding by making freq-table-hz
disallowed, enforcing operating-points-v2, and renaming and expanding the
clock requirements for MT8195 and MT8192 platforms. It also documents various
power supply pins and adds a new example for MT8195.

>     Disallow freq-table-hz and move to operating-points-v2. It's fine to
>     break compatibility here, as the binding is currently unused and would
>     be impossible to correctly use in its current state.

Is this description accurate regarding the binding being unused?

Looking at arch/arm64/boot/dts/mediatek/mt8195.dtsi, there is an active
mainline user of the mediatek,mt8195-ufshci compatible string:

arch/arm64/boot/dts/mediatek/mt8195.dtsi:ufshci() {
        ...
        compatible = "mediatek,mt8195-ufshci";
        ...
        clock-names = "ufs", "ufs_aes", "ufs_tick",
                      "unipro_sysclk", "unipro_tick",
                      "unipro_mp_bclk", "ufs_tx_symbol",
                      "ufs_mem_sub";
        freq-table-hz = <0 0>, <0 0>, <0 0>, <0 0>;
        ...
}

Will this change cause dtbs_check validation to fail for the MT8195 platform
since it still relies on freq-table-hz and the old ufs-prefixed clock names?

> diff --git a/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml b/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml
> index 15c347f5e6604..945cb986b06b7 100644
> --- a/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml
> +++ b/Documentation/devicetree/bindings/ufs/mediatek,ufs.yaml

[ ... ]

> @@ -54,29 +96,41 @@ allOf:
>        properties:
>          compatible:
>            contains:
> -            enum:
> -              - mediatek,mt8195-ufshci

[ ... ]

> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: mediatek,mt8195-ufshci
> +    then:
> +      properties:
> +        clocks:
> +          minItems: 10
> +        clock-names:
> +          minItems: 10

[Severity: Medium]
Does enforcing a minimum of 10 clocks here break existing in-tree device
trees?

As shown above, the existing mt8195.dtsi specifies exactly 8 clocks. Because
this patch requires 10 clocks, explicitly requires the new names without the
ufs_ prefix, and forbids freq-table-hz, will it break backward compatibility
and leave the tree in a broken state for MT8195 users?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261016-mt8196-ufs-v14-0-e8d565e0cd45@collabora.com?part=2