Hi Leo,
On 2017/12/22 9:37, Wei Xu wrote:
> Hi Leo,
>
> On 2017/12/12 9:12, Leo Yan wrote:
>> Thanks a lot for Vincent Guittot careful work to find bug for 'CPU_NAP'
>> idle state. From ftrace log we can observe CA73 CPUs can be easily
>> waken up from 'CPU_NAP' state but the 'waken up' CPUs doesn't handle
>> anything and sleep again; so there have tons of trace events for CA73
>> CPUs entering and exiting idle state.
>>
>> On Hi3660 CA73 has retention state 'CPU_NAP' for CPU idle, this state we
>> set its psci parameter as '0x0000001' and from this parameter it can
>> calculate state id is 1. Unfortunately ARM trusted firmware (ARM-TF)
>> takes 1 as a invalid value for state id, so the CPU cannot enter idle
>> state and directly bail out to kernel.
>>
>> We want to create good practice for psci parameters platform definition,
>> so review the psci specification. The spec "ARM Power State Coordination
>> Interface - Platform Design Document (ARM DEN 0022D)" recommends state
>> ID in chapter "6.5 Recommended StateID Encoding". The recommended power
>> state IDs can be presented by below listed values; and it divides into
>> three fields, every field can use 4 bits to present power states
>> corresponding to core level, cluster level and system level:
>> 0: Run
>> 1: Standby
>> 2: Retention
>> 3: Powerdown
>>
>> This commit changes psci parameter to compliance with the suggested
>> state ID in the doc. Except we change 'CPU_NAP' state psci parameter
>> to '0x0000002', this commit also changes 'CPU_SLEEP' and 'CLUSTER_SLEEP'
>> state parameters to '0x0010003' and '0x1010033' respectively.
>>
>> Credits to Daniel, Sudeep and Soby for suggestion and consolidation.
>>
>> Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
>> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
>> Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
>> Cc: Soby Mathew <Soby.Mathew@xxxxxxx>
>> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
>> ---
>
> Applied into hisilicon dt tree.
> Thanks!
Sorry, since this patch is still under discussion,
I will drop it firstly.
Thanks!
Best Regards,
Wei
>
> Best Regards,
> Wei
>
>> arch/arm64/boot/dts/hisilicon/hi3660.dtsi | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
>> index ab0b95b..99d5a46 100644
>> --- a/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
>> +++ b/arch/arm64/boot/dts/hisilicon/hi3660.dtsi
>> @@ -147,7 +147,7 @@
>>
>> CPU_NAP: cpu-nap {
>> compatible = "arm,idle-state";
>> - arm,psci-suspend-param = <0x0000001>;
>> + arm,psci-suspend-param = <0x0000002>;
>> entry-latency-us = <7>;
>> exit-latency-us = <2>;
>> min-residency-us = <15>;
>> @@ -156,7 +156,7 @@
>> CPU_SLEEP: cpu-sleep {
>> compatible = "arm,idle-state";
>> local-timer-stop;
>> - arm,psci-suspend-param = <0x0010000>;
>> + arm,psci-suspend-param = <0x0010003>;
>> entry-latency-us = <40>;
>> exit-latency-us = <70>;
>> min-residency-us = <3000>;
>> @@ -165,7 +165,7 @@
>> CLUSTER_SLEEP_0: cluster-sleep-0 {
>> compatible = "arm,idle-state";
>> local-timer-stop;
>> - arm,psci-suspend-param = <0x1010000>;
>> + arm,psci-suspend-param = <0x1010033>;
>> entry-latency-us = <500>;
>> exit-latency-us = <5000>;
>> min-residency-us = <20000>;
>> @@ -174,7 +174,7 @@
>> CLUSTER_SLEEP_1: cluster-sleep-1 {
>> compatible = "arm,idle-state";
>> local-timer-stop;
>> - arm,psci-suspend-param = <0x1010000>;
>> + arm,psci-suspend-param = <0x1010033>;
>> entry-latency-us = <1000>;
>> exit-latency-us = <5000>;
>> min-residency-us = <20000>;
>>
--
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