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.guit...@linaro.org>
> Cc: Daniel Lezcano <daniel.lezc...@linaro.org>
> Cc: Sudeep Holla <sudeep.ho...@arm.com>
> Cc: Soby Mathew <soby.mat...@arm.com>
> Signed-off-by: Leo Yan <leo....@linaro.org>
> ---
Applied into hisilicon dt tree.
Thanks!
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>;
>
