Re: [PATCH v3 1/2] dt-bindings: remoteproc: qcom,shikra-pas: Allow 3 IOMMUs for LPAICP

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] dt-bindings: remoteproc: qcom,shikra-pas: Broken inheritance drops #cooling-cells
- [Low] dt-bindings: remoteproc: qcom,shikra-pas: Missing minItems: 3 for iommus
--

commit e7d5ea05bb3cbb1ebebda930478b2df76f82dd6e
Author: Komal Bajaj <komal.bajaj@oss.qualcomm.com>

dt-bindings: remoteproc: qcom,shikra-pas: Allow 3 IOMMUs for LPAICP

This patch removes the common PAS schema inheritance (qcom,pas-common.yaml)
and specifies local IOMMU entry limits for each Shikra PAS compatible. It
allows 3 IOMMU entries for the LPAICP variant, resolving a conflict where the
common schema previously limited iommus to a single entry.

> diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,shikra-pas.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,shikra-pas.yaml
> index 34a2f15e93616..4196f61a8ba0c 100644
> --- a/Documentation/devicetree/bindings/remoteproc/qcom,shikra-pas.yaml
> +++ b/Documentation/devicetree/bindings/remoteproc/qcom,shikra-pas.yaml

[ ... ]

> @@ -92,10 +95,14 @@ required:
>    - compatible
>    - reg
>    - memory-region
> +  - clocks
> +  - clock-names
> +  - interrupts
> +  - interrupt-names
> +  - qcom,smem-states
> +  - qcom,smem-state-names
>  
>  allOf:
> -  - $ref: /schemas/remoteproc/qcom,pas-common.yaml#
> -
>    - if:
>        properties:
>          compatible:

[Severity: Medium]
Does removing the $ref to qcom,pas-common.yaml# cause the schema to lose
support for standard PAS features like #cooling-cells?

Because json-schema allOf cannot loosen constraints, the inheritance from the
common PAS schema was severed to resolve the conflict with the inherited
maxItems: 1 constraint on iommus.

However, this prevents qcom,shikra-pas.yaml from receiving future updates to
the common PAS schema and silently drops support for inherited properties.
Since unevaluatedProperties: false is used, any attempt to use #cooling-cells
in a Shikra PAS node will now trigger a schema validation error.

Would it be better to relax the iommus: maxItems constraint in
qcom,pas-common.yaml (e.g., to 3 or higher) and apply stricter local
constraints where needed, rather than breaking the inheritance chain?

[ ... ]

> @@ -134,6 +143,8 @@ allOf:
>            minItems: 2
>          firmware-name:
>            minItems: 2
> +        iommus:
> +          maxItems: 3

[Severity: Low]
Should there be a minItems: 3 constraint added here?

The commit message explicitly states: "The Shikra LPAICP PAS requires three
IOMMU entries." However, maxItems only sets an upper bound.

Without minItems: 3, incomplete device tree overlays with only 1 or 2 iommus
entries will silently pass schema validation despite violating the strict
hardware requirement.

Making the property mandatory via required: would be incorrect since iommus
is intentionally omitted from the base DT and added via an EL2 overlay, but
when the property is present, the 3-entry minimum size constraint must be
enforced.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261005-shikra-el2-v3-0-618f7343695c@oss.qualcomm.com?part=1