Re: [PATCH DNM v3 8/8] arm64: dts: qcom: kaanapali: Add MPAM MSC nodes for the L2 caches

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dts: merging example code explicitly marked as not intended for upstream
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commit 9a283550c6d64193c89c11f63f98ea9257487934
Author: Yin Li <yin.li@oss.qualcomm.com>

arm64: dts: qcom: kaanapali: Add MPAM MSC nodes for the L2 caches

This commit adds disabled MPAM MSC device nodes under the L2 caches in the
Kaanapali device tree. These nodes are intended to allow direct MMIO access
to the MSCs in local test setups where production firmware restrictions are
bypassed.

> The nodes are disabled by default. Production firmware does not expose
> MSC register access to the OS, so these nodes can only be enabled on a
> local test setup where firmware permits direct MMIO access to the MSCs.
> This DTS is therefore only an example for other platform DT authors and
> is not intended to be merged.

[Severity: Medium]
Is this patch intended for mainline inclusion? The commit message explicitly
states that this is an example for local test setups and is not intended to
be merged.

> diff --git a/arch/arm64/boot/dts/qcom/kaanapali.dtsi b/arch/arm64/boot/dts/qcom/kaanapali.dtsi
> index 131fd2a16c545..b1dcb1e9c570c 100644
> --- a/arch/arm64/boot/dts/qcom/kaanapali.dtsi
> +++ b/arch/arm64/boot/dts/qcom/kaanapali.dtsi
[ ... ]
> @@ -531,6 +519,44 @@ soccp_smp2p_in: slave-kernel {
>  		};
>  	};
>  
> +	l2_0: l2-cache-0 {
> +		compatible = "cache";
> +		cache-level = <2>;
> +		cache-unified;
> +		cache-size = <0xc00000>;
> +		ranges;
> +
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +
> +		msc@19870000 {
> +			compatible = "arm,mpam-msc";
> +			reg = <0x0 0x19870000 0x0 0x10000>;
> +			arm,not-ready-us = <1>;
> +			status = "disabled";
> +		};

[Severity: Medium]
Should these test-only nodes be dropped to avoid polluting the production
device tree? Since production firmware does not expose MSC register access to
the OS, describing this inaccessible hardware configuration seems strictly tied
to local debug environments rather than an upstream hardware description.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261008-mpam-resctrl-dt-knp-support-v3-0-35196c2b43bf@oss.qualcomm.com?part=8