Hi Heiko:

On 2018?08?10? 04:09, Heiko Stuebner wrote:

Am Mittwoch, 6. Juli 2016, 10:20:54 CEST schrieb Caesar Wang:

quoted

 arch/arm64/boot/dts/rockchip/rk3399.dtsi | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
index a6dd623..12ce265 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi

@@ -101,6 +101,18 @@
 			};
 		};
 
+		idle-states {
+			entry-method = "psci";
+			cpu_sleep: cpu-sleep-0 {
+				compatible = "arm,idle-state";
+				local-timer-stop;
+				arm,psci-suspend-param = <0x0010000>;
+				entry-latency-us = <350>;
+				exit-latency-us = <600>;
+				min-residency-us = <1150>;

Looking at the chromeos kernel, there are some more patches adapting
this idle-state to use different timings.

Yes, we have another values. So the values of this patch are wrong.

There also was a cluster-idle state added for a while but that seems to
cause audio issues according to the CrOS history.

DMA or Audio driver should add PM_QOS_CPU_DMA_LATENCY or other methods to avoid the effects of idle.
Idle itself is good.

Thanks!