linux-kernel - Re: [PATCH 05/24] arm64: dts: qcom: glymur: Add cpu idle states

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2055e6a8-dace-4ee9-a74b-0e3bf2d58fb7@oss.qualcomm.com>
Date: Thu, 25 Sep 2025 12:25:14 +0200
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Pankaj Patil <pankaj.patil@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>
Cc: linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Maulik Shah <maulik.shah@....qualcomm.com>
Subject: Re: [PATCH 05/24] arm64: dts: qcom: glymur: Add cpu idle states

On 9/25/25 8:32 AM, Pankaj Patil wrote:
> From: Maulik Shah <maulik.shah@....qualcomm.com>
> 
> Add CPU power domains

The commit message could say something about what kind of states
are being added, what their impact on the running system is, etc..

[...]

> +		idle-states {
> +			entry-method = "psci";
> +
> +			CLUSTER0_C4: cpu-sleep-0 {
> +				compatible = "arm,idle-state";
> +				idle-state-name = "ret";
> +				arm,psci-suspend-param = <0x00000004>;
> +				entry-latency-us = <180>;
> +				exit-latency-us = <320>;
> +				min-residency-us = <1000>;
> +			};
> +
> +			CLUSTER1_C4: cpu-sleep-1 {
> +				compatible = "arm,idle-state";
> +				idle-state-name = "ret";
> +				arm,psci-suspend-param = <0x00000004>;
> +				entry-latency-us = <180>;
> +				exit-latency-us = <320>;
> +				min-residency-us = <1000>;
> +			};
> +
> +			CLUSTER2_C4: cpu-sleep-2 {
> +				compatible = "arm,idle-state";
> +				idle-state-name = "ret";
> +				arm,psci-suspend-param = <0x00000004>;
> +				entry-latency-us = <180>;
> +				exit-latency-us = <320>;
> +				min-residency-us = <1000>;
> +			};

All three are identical (should they be?), just call it CPU_C4 and de-
duplicate it (unless the framework would read that as "all CPUs in the
system must sleep at the same time" which I don't know if it would)

> +
> +			cluster0_cl5: cluster-sleep-0 {
> +				compatible = "domain-idle-state";
> +				idle-state-name = "ret";
> +				arm,psci-suspend-param = <0x01000054>;
> +				entry-latency-us = <2000>;
> +				exit-latency-us = <2000>;
> +				min-residency-us = <9000>;
> +			};
> +
> +			cluster1_cl5: cluster-sleep-1 {
> +				compatible = "domain-idle-state";
> +				idle-state-name = "ret";
> +				arm,psci-suspend-param = <0x01000054>;
> +				entry-latency-us = <2000>;
> +				exit-latency-us = <2000>;
> +				min-residency-us = <9000>;
> +			};
> +
> +			cluster2_cl5: cluster-sleep-2 {
> +				compatible = "domain-idle-state";
> +				idle-state-name = "ret";
> +				arm,psci-suspend-param = <0x01000054>;
> +				entry-latency-us = <2000>;
> +				exit-latency-us = <2000>;
> +				min-residency-us = <9000>;
> +			};

ditto

> +
> +			APSS_OFF: cluster-ss3 {

labels must be lowercase

> +				compatible = "domain-idle-state";
> +				idle-state-name = "apps-pc";
> +				entry-latency-us = <2800>;
> +				exit-latency-us = <4400>;
> +				min-residency-us = <10150>;
> +				arm,psci-suspend-param = <0x0200C354>;

lowercase hex, please

also, this node oddly puts arm,psci-suspend-param at a different place,
please align it with the prvious ones

[...]

> +		CLUSTER3_PD: power-domain-cpu-cluster3 {

"SYSTEM_PD"?
> +			#power-domain-cells = <0>;
> +			domain-idle-states = <&APSS_OFF>;

Does it make sense to include some shallower idle states?

Konrad