Re: [PATCH 4/7] dt-bindings: watchdog: mediatek,mtk-wdt: remove mt6589 fallback items

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:

New issues:
- [Medium] Removing the fallback `items` block breaks schema validation for existing older Device Trees.

Pre-existing issues:
- [High] This problem wasn't introduced by this patch, but the schema fails to conditionally enforce `#reset-cells` as a required property for watchdog variants that act as reset providers.
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--- Patch [4]: [PATCH 4/7] dt-bindings: watchdog: mediatek,mtk-wdt: remove mt6589 fallback items ---
commit 51d21b22f4b3e7a458ffe7ba34258074ee5dc9ac
Author: Akari Tsuyukusa <[email protected]>

dt-bindings: watchdog: mediatek,mtk-wdt: remove mt6589 fallback items

This commit removes the fallback items block for the mediatek,mt6589-wdt
compatible string from the MediaTek watchdog binding. It retains only the
flat enum, under the premise that all DTS files have been converted to
standalone compatibles.

> diff --git a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
> index f4eaa5f7c5bc3..2411c02f1cb0f 100644
> --- a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
> @@ -42,21 +42,6 @@ properties:
>            - mediatek,mt8195-wdt
>            - mediatek,mt8365-wdt
>            - mediatek,mt8516-wdt
> -      - items:
> -          - enum:
> -              - mediatek,mt2701-wdt
> -              - mediatek,mt6572-wdt
> -              - mediatek,mt6582-wdt

[Severity: Medium]
Will removing this fallback block cause validation regressions for existing
older device trees?

If users run dtbs_check against older device trees containing compatible
arrays like "mediatek,mt8516-wdt", "mediatek,mt6589-wdt", they will now
fail validation.

[ ... ]

Looking at the required properties list further down in
Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml:

>   '#reset-cells':
>     const: 1
> 
> required:
>   - compatible
>   - reg

[Severity: High]
This is a pre-existing issue, but does the schema fail to conditionally
enforce #reset-cells as a required property for watchdog variants that act
as reset providers?

If device trees omit this property for reset provider variants like
"mediatek,mt8188-wdt", they silently pass validation. Dependent subsystems
relying on the reset line will then fail at runtime when attempting to use
the undocumented functionality.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=4