| Message ID | cfd8de4b2ad1cfd7b0f1a0706c0b6b918e1ebffc.1527244201.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Wed, May 30, 2018 at 6:38 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote: > On 29-05-18, 15:18, Krzysztof Kozlowski wrote: >> Thanks for the patch. >> >> In case of Exynos, the booting CPU always has these information in DT >> and the booting CPU cannot be changed (chosen by firmware/hardware >> configuration). > > But can the booting CPU be offlined ? > > If yes, then this is how things are broken right now. > > Build cpufreq driver as module, boot kernel, hotplug out CPU0, insert > cpufreq driver and that will try to find these properties in CPU1. OK, I see the possibility although it is still far away from use cases. You cannot hotplug booting CPU (CPU0) on Exynos kernels. It never worked. Strictly speaking - offlining will work. But bringing it online will likely hang the system. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 30-05-18, 14:32, Krzysztof Kozlowski wrote: > OK, I see the possibility although it is still far away from use > cases. You cannot hotplug booting CPU (CPU0) on Exynos kernels. It > never worked. Strictly speaking - offlining will work. But bringing it > online will likely hang the system. True and I used the following out of tree patch for a long time for my dual A15 exynos to make hotplug work. https://git.linaro.org/people/vireshk/backup/linux.git/commit/?h=bkp/exynos/hotplug&id=aab8a906a70b8f1fb15a4b7bd2ee27e6dcabf79d -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi index 962af97c1883..aff5d66ae058 100644 --- a/arch/arm/boot/dts/exynos3250.dtsi +++ b/arch/arm/boot/dts/exynos3250.dtsi @@ -78,6 +78,22 @@ compatible = "arm,cortex-a7"; reg = <1>; clock-frequency = <1000000000>; + clocks = <&cmu CLK_ARM_CLK>; + clock-names = "cpu"; + #cooling-cells = <2>; + + operating-points = < + 1000000 1150000 + 900000 1112500 + 800000 1075000 + 700000 1037500 + 600000 1000000 + 500000 962500 + 400000 925000 + 300000 887500 + 200000 850000 + 100000 850000 + >; }; }; diff --git a/arch/arm/boot/dts/exynos4210.dtsi b/arch/arm/boot/dts/exynos4210.dtsi index 88fb47cef9a8..b6091c27f155 100644 --- a/arch/arm/boot/dts/exynos4210.dtsi +++ b/arch/arm/boot/dts/exynos4210.dtsi @@ -55,6 +55,19 @@ device_type = "cpu"; compatible = "arm,cortex-a9"; reg = <0x901>; + clocks = <&clock CLK_ARM_CLK>; + clock-names = "cpu"; + clock-latency = <160000>; + + operating-points = < + 1200000 1250000 + 1000000 1150000 + 800000 1075000 + 500000 975000 + 400000 975000 + 200000 950000 + >; + #cooling-cells = <2>; /* min followed by max */ }; }; diff --git a/arch/arm/boot/dts/exynos4412.dtsi b/arch/arm/boot/dts/exynos4412.dtsi index 7b43c10c510b..51f72f0327e5 100644 --- a/arch/arm/boot/dts/exynos4412.dtsi +++ b/arch/arm/boot/dts/exynos4412.dtsi @@ -49,21 +49,30 @@ device_type = "cpu"; compatible = "arm,cortex-a9"; reg = <0xA01>; + clocks = <&clock CLK_ARM_CLK>; + clock-names = "cpu"; operating-points-v2 = <&cpu0_opp_table>; + #cooling-cells = <2>; /* min followed by max */ }; cpu@a02 { device_type = "cpu"; compatible = "arm,cortex-a9"; reg = <0xA02>; + clocks = <&clock CLK_ARM_CLK>; + clock-names = "cpu"; operating-points-v2 = <&cpu0_opp_table>; + #cooling-cells = <2>; /* min followed by max */ }; cpu@a03 { device_type = "cpu"; compatible = "arm,cortex-a9"; reg = <0xA03>; + clocks = <&clock CLK_ARM_CLK>; + clock-names = "cpu"; operating-points-v2 = <&cpu0_opp_table>; + #cooling-cells = <2>; /* min followed by max */ }; }; diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi index 2daf505b3d08..69648f83b8b4 100644 --- a/arch/arm/boot/dts/exynos5250.dtsi +++ b/arch/arm/boot/dts/exynos5250.dtsi @@ -84,6 +84,29 @@ compatible = "arm,cortex-a15"; reg = <1>; clock-frequency = <1700000000>; + clocks = <&clock CLK_ARM_CLK>; + clock-names = "cpu"; + clock-latency = <140000>; + + operating-points = < + 1700000 1300000 + 1600000 1250000 + 1500000 1225000 + 1400000 1200000 + 1300000 1150000 + 1200000 1125000 + 1100000 1100000 + 1000000 1075000 + 900000 1050000 + 800000 1025000 + 700000 1012500 + 600000 1000000 + 500000 975000 + 400000 950000 + 300000 937500 + 200000 925000 + >; + #cooling-cells = <2>; /* min followed by max */ }; };
The cooling device properties, like "#cooling-cells" and "dynamic-power-coefficient", should either be present for all the CPUs of a cluster or none. If these are present only for a subset of CPUs of a cluster then things will start falling apart as soon as the CPUs are brought online in a different order. For example, this will happen because the operating system looks for such properties in the CPU node it is trying to bring up, so that it can register a cooling device. Add such missing properties. Fix other missing properties (clocks, OPP, clock latency) as well to make it all work. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- arch/arm/boot/dts/exynos3250.dtsi | 16 ++++++++++++++++ arch/arm/boot/dts/exynos4210.dtsi | 13 +++++++++++++ arch/arm/boot/dts/exynos4412.dtsi | 9 +++++++++ arch/arm/boot/dts/exynos5250.dtsi | 23 +++++++++++++++++++++++ 4 files changed, 61 insertions(+) -- 2.15.0.194.g9af6a3dea062 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html