Re: [PATCH 01/22] dt-bindings: media: qcom,venus-common: Allow IOVA reservation memory-region

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The patch updates `qcom,venus-common.yaml` to permit a second `memory-region` phandle for an IOMMU IOVA reservation, but fails to remove a stale `maxItems: 1` constraint from `qcom,sc7180-venus.yaml`. This prevents SC7180 devices from successfully validating if they supply the newly permitted second region.
--

--- Patch [1]: [PATCH 01/22] dt-bindings: media: qcom,venus-common: Allow IOVA reservation memory-region ---
commit 44e20424e211e02ef9914abe4592c185ad0d75ac
Author: Vikash Garodia <vikash.garodia@oss.qualcomm.com>

dt-bindings: media: qcom,venus-common: Allow IOVA reservation memory-region

Non-pixel stream IDs should not allocate IOVA space from the 0 to 600MB
restricted region, as this region is reserved exclusively for secure
non-pixel.

In addition to the firmware-loaded codec carveout, platforms need to
declare an IOMMU IOVA reservation (a reserved-memory node with
iommu-addresses) to keep DMA away from restricted IOVA range.

Permit a second memory-region phandle for this purpose, and describe the
meaning of each entry so the ordering is unambiguous.

> diff --git a/Documentation/devicetree/bindings/media/qcom,venus-common.yaml b/Documentation/devicetree/bindings/media/qcom,venus-common.yaml
> index 59a3fde846d21..0be2f9119e782 100644
> --- a/Documentation/devicetree/bindings/media/qcom,venus-common.yaml
> +++ b/Documentation/devicetree/bindings/media/qcom,venus-common.yaml
> @@ -37,7 +37,10 @@ properties:
>      maxItems: 20
>  
>    memory-region:
> -    maxItems: 1
> +    minItems: 1
> +    items:
> +      - description: Firmware-loaded codec carveout
> +      - description: IOMMU IOVA reservation region

[Severity: Medium]
Since this patch expands the common schema to allow two memory-region items,
should the local constraints in related variant schemas also be updated?

For example, the local constraint in qcom,sc7180-venus.yaml restricts the
items to 1:

Documentation/devicetree/bindings/media/qcom,sc7180-venus.yaml:properties.memory-region {
    ...
  memory-region:
    maxItems: 1
    ...
}

Because dt-schema evaluates a logical AND between local constraints and
the included $ref schemas, won't SC7180 device trees fail dt_binding_check
validation if they declare the newly permitted IOVA reservation region?

>  
>    power-domains:
>      minItems: 1

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260807-iris_iova_600mb_fix-v1-0-3996f67e33f9@oss.qualcomm.com?part=1