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

[Daniel Lezcano]

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@xxxxxxxxxx>
> ---
>  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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