Re: [PATCH v2 7/9] arm64: dts: qcom: msm8998: Add PSCI cpuidle low power states

From: Jeffrey Hugo
Date: Mon Sep 30 2019 - 18:20:30 EST

Amit, the merged version of the below change causes a boot failure
(nasty hang, sometimes with RCU stalls) on the msm8998 laptops. Oddly
enough, it seems to be resolved if I remove the cpu-idle-states
property from one of the cpu nodes.

I see no issues with the msm8998 MTP.

Do you have any suggestions on how we might debug this?

On Tue, May 21, 2019 at 3:38 AM Amit Kucheria <amit.kucheria@xxxxxxxxxx> wrote:
>
> Add device bindings for cpuidle states for cpu devices.
>
> Cc: Marc Gonzalez <marc.w.gonzalez@xxxxxxx>
> Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx>
> Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> ---
> arch/arm64/boot/dts/qcom/msm8998.dtsi | 50 +++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/msm8998.dtsi b/arch/arm64/boot/dts/qcom/msm8998.dtsi
> index 3fd0769fe648..54810980fcf9 100644
> --- a/arch/arm64/boot/dts/qcom/msm8998.dtsi
> +++ b/arch/arm64/boot/dts/qcom/msm8998.dtsi
> @@ -78,6 +78,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x0>;
> enable-method = "psci";
> + cpu-idle-states = <&LITTLE_CPU_SLEEP_0 &LITTLE_CPU_SLEEP_1>;
> efficiency = <1024>;
> next-level-cache = <&L2_0>;
> L2_0: l2-cache {
> @@ -97,6 +98,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x1>;
> enable-method = "psci";
> + cpu-idle-states = <&LITTLE_CPU_SLEEP_0 &LITTLE_CPU_SLEEP_1>;
> efficiency = <1024>;
> next-level-cache = <&L2_0>;
> L1_I_1: l1-icache {
> @@ -112,6 +114,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x2>;
> enable-method = "psci";
> + cpu-idle-states = <&LITTLE_CPU_SLEEP_0 &LITTLE_CPU_SLEEP_1>;
> efficiency = <1024>;
> next-level-cache = <&L2_0>;
> L1_I_2: l1-icache {
> @@ -127,6 +130,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x3>;
> enable-method = "psci";
> + cpu-idle-states = <&LITTLE_CPU_SLEEP_0 &LITTLE_CPU_SLEEP_1>;
> efficiency = <1024>;
> next-level-cache = <&L2_0>;
> L1_I_3: l1-icache {
> @@ -142,6 +146,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x100>;
> enable-method = "psci";
> + cpu-idle-states = <&BIG_CPU_SLEEP_0 &BIG_CPU_SLEEP_1>;
> efficiency = <1536>;
> next-level-cache = <&L2_1>;
> L2_1: l2-cache {
> @@ -161,6 +166,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x101>;
> enable-method = "psci";
> + cpu-idle-states = <&BIG_CPU_SLEEP_0 &BIG_CPU_SLEEP_1>;
> efficiency = <1536>;
> next-level-cache = <&L2_1>;
> L1_I_101: l1-icache {
> @@ -176,6 +182,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x102>;
> enable-method = "psci";
> + cpu-idle-states = <&BIG_CPU_SLEEP_0 &BIG_CPU_SLEEP_1>;
> efficiency = <1536>;
> next-level-cache = <&L2_1>;
> L1_I_102: l1-icache {
> @@ -191,6 +198,7 @@
> compatible = "arm,armv8";
> reg = <0x0 0x103>;
> enable-method = "psci";
> + cpu-idle-states = <&BIG_CPU_SLEEP_0 &BIG_CPU_SLEEP_1>;
> efficiency = <1536>;
> next-level-cache = <&L2_1>;
> L1_I_103: l1-icache {
> @@ -238,6 +246,48 @@
> };
> };
> };
> +
> + idle-states {
> + entry-method = "psci";
> +
> + LITTLE_CPU_SLEEP_0: cpu-sleep-0-0 {
> + compatible = "arm,idle-state";
> + idle-state-name = "little-retention";
> + arm,psci-suspend-param = <0x00000002>;
> + entry-latency-us = <43>;
> + exit-latency-us = <86>;
> + min-residency-us = <200>;
> + };
> +
> + LITTLE_CPU_SLEEP_1: cpu-sleep-0-1 {
> + compatible = "arm,idle-state";
> + idle-state-name = "little-power-collapse";
> + arm,psci-suspend-param = <0x00000003>;
> + entry-latency-us = <100>;
> + exit-latency-us = <612>;
> + min-residency-us = <1000>;
> + local-timer-stop;
> + };
> +
> + BIG_CPU_SLEEP_0: cpu-sleep-1-0 {
> + compatible = "arm,idle-state";
> + idle-state-name = "big-retention";
> + arm,psci-suspend-param = <0x00000002>;
> + entry-latency-us = <41>;
> + exit-latency-us = <82>;
> + min-residency-us = <200>;
> + };
> +
> + BIG_CPU_SLEEP_1: cpu-sleep-1-1 {
> + compatible = "arm,idle-state";
> + idle-state-name = "big-power-collapse";
> + arm,psci-suspend-param = <0x00000003>;
> + entry-latency-us = <100>;
> + exit-latency-us = <525>;
> + min-residency-us = <1000>;
> + local-timer-stop;
> + };
> + };
> };
>
> firmware {
> --
> 2.17.1
>