Re: [PATCHv1 6/8] arm64: dts: qcom: msm8996: Add PSCI cpuidle low power states

Daniel Lezcano
2019-05-17T15:55:26Z

On 10/05/2019 13:29, Amit Kucheria wrote:
> Add device bindings for cpuidle states for cpu devices.
>
> Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
> ---
> arch/arm64/boot/dts/qcom/msm8996.dtsi | 28 +++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
> index c761269caf80..b615bcb9e351 100644
> --- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
> +++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
> @@ -95,6 +95,7 @@
> compatible = "qcom,kryo";
> reg = <0x0 0x0>;
> enable-method = "psci";
> + cpu-idle-states = <&LITTLE_CPU_PD>;

It is the same micro architecture, the CPUS differ by their max OPP.
Shall we call it really little?

I take the opportunity to report the capacity-dmips-mhz attribute is
missing. The max capacity computation is not triggered, thus the
scheduler see the same capacity for both cluster even if one has less
OPP. Adding capacity-dmips-mhz = <1024>; to all CPUs will fix it.

> next-level-cache = <&L2_0>;
> L2_0: l2-cache {
> compatible = "cache";
> @@ -107,6 +108,7 @@
> compatible = "qcom,kryo";
> reg = <0x0 0x1>;
> enable-method = "psci";
> + cpu-idle-states = <&LITTLE_CPU_PD>;
> next-level-cache = <&L2_0>;
> };
>
> @@ -115,6 +117,7 @@
> compatible = "qcom,kryo";
> reg = <0x0 0x100>;
> enable-method = "psci";
> + cpu-idle-states = <&BIG_CPU_PD>;
> next-level-cache = <&L2_1>;
> L2_1: l2-cache {
> compatible = "cache";
> @@ -127,6 +130,7 @@
> compatible = "qcom,kryo";
> reg = <0x0 0x101>;
> enable-method = "psci";
> + cpu-idle-states = <&BIG_CPU_PD>;
> next-level-cache = <&L2_1>;
> };
>
> @@ -151,6 +155,30 @@
> };
> };
> };
> +
> + idle-states {
> + entry-method="psci";
> +
> + LITTLE_CPU_PD: little-power-down {
> + compatible = "arm,idle-state";
> + idle-state-name = "standalone-power-collapse";
> + arm,psci-suspend-param = <0x00000004>;
> + entry-latency-us = <40>;
> + exit-latency-us = <40>;
> + min-residency-us = <300>;
> + local-timer-stop;
> + };
> +
> + BIG_CPU_PD: big-power-down {
> + compatible = "arm,idle-state";
> + idle-state-name = "standalone-power-collapse";
> + arm,psci-suspend-param = <0x00000004>;
> + entry-latency-us = <40>;
> + exit-latency-us = <40>;
> + min-residency-us = <300>;
> + local-timer-stop;
> + };
> + };
> };
>
> thermal-zones {
>

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