Re: [PATCH v9 7/9] arm64: dts: qcom: agatti: Add OPE node

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dts: overlapping iommu stream IDs artificially merge IOMMU groups
--

commit f837397d169ca6bd9f29b986ea39a8a6e4ab9b26
Author: Loic Poulain <loic.poulain@oss.qualcomm.com>

arm64: dts: qcom: agatti: Add OPE node

Add the Offline Processing Engine (OPE) device tree node for the
Agatti platform (QCM2290).

> diff --git a/arch/arm64/boot/dts/qcom/agatti.dtsi b/arch/arm64/boot/dts/qcom/agatti.dtsi
> index 590bd2432d85b..69237959adc15 100644
> --- a/arch/arm64/boot/dts/qcom/agatti.dtsi
> +++ b/arch/arm64/boot/dts/qcom/agatti.dtsi
> @@ -1984,6 +1984,83 @@ port@1 {
>  			};
>  		};
>  
> +		isp_ope: isp@5c42000 {
> +			compatible = "qcom,qcm2290-camss-ope";

[ ... ]

> +			interconnect-names = "config",
> +					     "data";
> +
> +			iommus = <&apps_smmu 0x800 0x0>,
> +				 <&apps_smmu 0x820 0x0>,
> +				 <&apps_smmu 0x840 0x0>;

[Severity: Medium]
Does this create a resource conflict with the existing camss node?

The newly added isp_ope node claims stream IDs 0x800, 0x820, and 0x840,
but these IDs are already claimed by the sibling camss node:

camss {
	...
	iommus = <&apps_smmu 0x400 0x0>,
		 <&apps_smmu 0x800 0x0>,
		 <&apps_smmu 0x820 0x0>,
		 <&apps_smmu 0x840 0x0>;
	...
}

Because these overlapping stream IDs are unconditionally parsed during boot,
arm_smmu_master_alloc_smes detects the exact SMR overlap and forcefully
places both distinct platform devices into the exact same IOMMU group.

Will this artificially intertwine their DMA domains, break device isolation,
and cause both drivers to map IOVAs into a shared context?

Should the OPE stream IDs be removed from the camss node since OPE is now
split into its own distinct platform device?

> +
> +			operating-points-v2 = <&ope_opp_table>;
> +			power-domains = <&gcc GCC_CAMSS_TOP_GDSC>,

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260923-camss-isp-ope-v9-0-86a75dc18b83@oss.qualcomm.com?part=7