Thread (19 messages) 19 messages, 3 authors, 2019-02-19

Re: [PATCH V6 5/7] arm64: dts: tegra210: add CPU idle states properties

From: Daniel Lezcano <hidden>
Date: 2019-02-15 15:47:39
Also in: linux-tegra

On 01/02/2019 17:16, Joseph Lo wrote:
quoted hunk ↗ jump to hunk
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.
 		};
 
 		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
+				idle-state-name = "c7-cpu-powergated";
"cpu-sleep"
+				status = "disabled";
+			};
 		};
 	};
 

-- 
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help