On 2/15/19 11:47 PM, Daniel Lezcano wrote:

On 01/02/2019 17:16, Joseph Lo wrote:

quoted

Add idle states properties for generic ARM CPU idle driver. This
includes a C7 state which is the power down state of CPU cores.

Signed-off-by: Joseph Lo <redacted>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
---
v6:
  * add ack tag from Jon.
v5:
  * no change
v4:
  * no change
v3:
  * no change
v2:
  * add entry-latency-us and exit-latency-us properties

Note:
This dt patch depends on the DT changes in below series.
http://patchwork.ozlabs.org/project/linux-tegra/list/?series=84380
---
  arch/arm64/boot/dts/nvidia/tegra210.dtsi | 19 +++++++++++++++++++
  1 file changed, 19 insertions(+)

diff --git a/arch/arm64/boot/dts/nvidia/tegra210.dtsi b/arch/arm64/boot/dts/nvidia/tegra210.dtsi
index 2b387364afc3..75534692604c 100644
--- a/arch/arm64/boot/dts/nvidia/tegra210.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra210.dtsi

@@ -1318,24 +1318,43 @@
  				 <&dfll>;
  			clock-names = "cpu_g", "pll_x", "pll_p", "dfll";
  			clock-latency = <300000>;
+			cpu-idle-states = <&C7>;

Please change the C7 name, that will be confusing with the C-state.

CPU_SLEEP would be nice and consistent with other drivers.

quoted

  		};
  
  		cpu@1 {
  			device_type = "cpu";
  			compatible = "arm,cortex-a57";
  			reg = <1>;
+			cpu-idle-states = <&C7>;
  		};
  
  		cpu@2 {
  			device_type = "cpu";
  			compatible = "arm,cortex-a57";
  			reg = <2>;
+			cpu-idle-states = <&C7>;
  		};
  
  		cpu@3 {
  			device_type = "cpu";
  			compatible = "arm,cortex-a57";
  			reg = <3>;
+			cpu-idle-states = <&C7>;
+		};
+
+		idle-states {
+			entry-method = "psci";
+
+			C7: c7 {
+				compatible = "arm,idle-state";
+				arm,psci-suspend-param = <0x40000007>;
+				entry-latency-us = <250>;
+				exit-latency-us = <100>;
+				min-residency-us = <1000>;
+				wakeup-latency-us = <130>;

Regarding the entry and the exit latency, the wakeup latency sounds a
bit small.

./devicetree/bindings/arm/idle-states.txt

quoted

+				idle-state-name = "c7-cpu-powergated";

"cpu-sleep"

Will fix them.

Thanks for reviewing,
Joseph

quoted

+				status = "disabled";
+			};
  		};
  	};
  

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