Re: [PATCH 5/8] iommu/arm-smmu-qcom: Add SM8450 MDSS compatible

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The SMMU client match table is missing several other modern Qualcomm MDSS compatibles (e.g., SM8350, SM8550, SM8650, SM8750, SM6125), causing them to suffer from unhandled context faults and broken display functionality.
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commit d66a67918c0ac7790f3063bd520102cd893aafb7
Author: Esteban Urrutia <esteuwu@proton.me>

iommu/arm-smmu-qcom: Add SM8450 MDSS compatible

This commit adds the SM8450 MDSS compatible to the Qualcomm SMMU client 
match table. This ensures the device is properly configured by the IOMMU 
driver to prevent unhandled context faults on the Snapdragon 8 Gen 1.

> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> index e2c914fccd6fc..795e8ec7e8faf 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> @@ -425,6 +425,7 @@ static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = {
>  	{ .compatible = "qcom,sm6375-mdss" },
>  	{ .compatible = "qcom,sm8150-mdss" },
>  	{ .compatible = "qcom,sm8250-mdss" },
> +	{ .compatible = "qcom,sm8450-mdss" },

[Severity: High]
This is a pre-existing issue, but while we are adding the sm8450-mdss 
compatible, should we also add other modern Qualcomm MDSS compatibles like 
sm8350, sm8550, sm8650, sm8750, and sm6125?

It looks like those SoCs might also lack a fallback qcom,mdss compatible 
and are currently missing from qcom_smmu_client_of_match.

If they are assigned a default DMA translation domain instead of the 
required bypass identity domain, wouldn't the MDSS wrapper generate native 
transactions that fail against the empty DMA domain, resulting in similar 
unhandled context faults?

>  	{ .compatible = "qcom,x1e80100-mdss" },
>  	{ }
>  };

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Sashiko AI review · https://sashiko.dev/#/patchset/20260622-sm8450-qol-v1-0-37e2ee8df9da@proton.me?part=5