Re: [PATCH 3/4] arm64: dts: qcom: milos: add CPU interconnect properties

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Adding `interconnects` properties to the CPU nodes without providing an `operating-points-v2` table causes the interconnect paths to be requested but never scaled, potentially hanging the system when sync_state drops the boot bandwidth to 0.
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--- Patch [3]: [PATCH 3/4] arm64: dts: qcom: milos: add CPU interconnect properties ---
commit dee7f3bb2bc8dddd64b4e3fb79a167672d8b6301
Author: Luca Weiss <luca.weiss@fairphone.com>

arm64: dts: qcom: milos: add CPU interconnect properties

This commit adds the interconnect entries for each CPU. It defines two
different paths: CPU to DDR, and L3 Cache from CPU to DDR interface.

> diff --git a/arch/arm64/boot/dts/qcom/milos.dtsi b/arch/arm64/boot/dts/qcom/milos.dtsi
> index 243210e6cb6eb..63dbd03512975 100644
> --- a/arch/arm64/boot/dts/qcom/milos.dtsi
> +++ b/arch/arm64/boot/dts/qcom/milos.dtsi

[ ... ]

> @@ -65,6 +66,11 @@ cpu0: cpu@0 {
>  
>  			qcom,freq-domain = <&cpufreq_hw 0>;
>  
> +			interconnects = <&gem_noc MASTER_APPSS_PROC QCOM_ICC_TAG_ACTIVE_ONLY
> +					 &mc_virt SLAVE_EBI1 QCOM_ICC_TAG_ACTIVE_ONLY>,
> +					<&epss_l3 MASTER_EPSS_L3_APPS
> +					 &epss_l3 SLAVE_EPSS_L3_SHARED>;
> +

[Severity: High]
Will this cause the system to hang when the interconnect driver's sync_state
callback is executed?

Since there is no operating-points-v2 table defined for the CPU nodes in this
device tree, qcom-cpufreq-hw will fail dev_pm_opp_of_add_table() with -ENODEV
and will not enable interconnect scaling.

However, because the interconnects property is present, a Device Link is
created that defers the interconnect provider's sync_state until
qcom-cpufreq-hw probes. Once it probes successfully without ever making a
bandwidth vote, sync_state will run and drop the initial boot bandwidth to 0.

Does this inadvertently throttle or disable the CPU interconnects by enforcing
a 0 vote on the CPU-to-DDR and L3 paths?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260710-milos-cpu-opp-v1-0-ae7f4b09bc77@fairphone.com?part=3