Re: [PATCH] arm64: dts: rockchip: Add idle-states to device tree for rk3399

Tao Huang
2018-08-12T16:24:45Z

Hi Heiko:

On 2018年08月10日 04:09, Heiko Stuebner wrote:
> Am Mittwoch, 6. Juli 2016, 10:20:54 CEST schrieb Caesar Wang:
>
>> 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!