Re: [RESEND PATCH v2 1/1] arm64: dts: qcom: sm6115: Add CPU idle-states
From: Bhupesh Sharma
Date: Sun Apr 02 2023 - 01:36:16 EST
On Sun, 2 Apr 2023 at 01:28, Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:
>
> On 01/04/2023 21:26, Bhupesh Sharma wrote:
> > Hi Konrad,
> >
> > On Sat, 1 Apr 2023 at 17:51, Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote:
> >>
> >>
> >>
> >> On 30.03.2023 21:33, Bhupesh Sharma wrote:
> >>> Add CPU idle-state nodes and power-domains in Qualcomm sm6115 SoC dtsi.
> >>>
> >>> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
> >>> ---
> >>> Changes since v1:
> >>> - v1 can be viewed here: https://lore.kernel.org/lkml/e5cda4cf-5c2a-a7ed-9e1d-1fe9f2cbef40@xxxxxxxxxx
> >>> - Addressed Konrad's comments on v1 and added GDHS and Power Collapse
> >>> cluster power states.
> >>>
> >>> arch/arm64/boot/dts/qcom/sm6115.dtsi | 136 +++++++++++++++++++++++++++
> >>> 1 file changed, 136 insertions(+)
> >>>
> >>> diff --git a/arch/arm64/boot/dts/qcom/sm6115.dtsi b/arch/arm64/boot/dts/qcom/sm6115.dtsi
> >>> index 2a51c938bbcb..b63395d476ed 100644
> >>> --- a/arch/arm64/boot/dts/qcom/sm6115.dtsi
> >>> +++ b/arch/arm64/boot/dts/qcom/sm6115.dtsi
> >>> @@ -45,6 +45,8 @@ CPU0: cpu@0 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_0>;
> >>> qcom,freq-domain = <&cpufreq_hw 0>;
> >>> + power-domains = <&CPU_PD0>;
> >>> + power-domain-names = "psci";
> >>> L2_0: l2-cache {
> >>> compatible = "cache";
> >>> cache-level = <2>;
> >>> @@ -61,6 +63,8 @@ CPU1: cpu@1 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_0>;
> >>> qcom,freq-domain = <&cpufreq_hw 0>;
> >>> + power-domains = <&CPU_PD1>;
> >>> + power-domain-names = "psci";
> >>> };
> >>>
> >>> CPU2: cpu@2 {
> >>> @@ -73,6 +77,8 @@ CPU2: cpu@2 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_0>;
> >>> qcom,freq-domain = <&cpufreq_hw 0>;
> >>> + power-domains = <&CPU_PD2>;
> >>> + power-domain-names = "psci";
> >>> };
> >>>
> >>> CPU3: cpu@3 {
> >>> @@ -85,6 +91,8 @@ CPU3: cpu@3 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_0>;
> >>> qcom,freq-domain = <&cpufreq_hw 0>;
> >>> + power-domains = <&CPU_PD3>;
> >>> + power-domain-names = "psci";
> >>> };
> >>>
> >>> CPU4: cpu@100 {
> >>> @@ -97,6 +105,8 @@ CPU4: cpu@100 {
> >>> dynamic-power-coefficient = <282>;
> >>> next-level-cache = <&L2_1>;
> >>> qcom,freq-domain = <&cpufreq_hw 1>;
> >>> + power-domains = <&CPU_PD4>;
> >>> + power-domain-names = "psci";
> >>> L2_1: l2-cache {
> >>> compatible = "cache";
> >>> cache-level = <2>;
> >>> @@ -113,6 +123,8 @@ CPU5: cpu@101 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_1>;
> >>> qcom,freq-domain = <&cpufreq_hw 1>;
> >>> + power-domains = <&CPU_PD5>;
> >>> + power-domain-names = "psci";
> >>> };
> >>>
> >>> CPU6: cpu@102 {
> >>> @@ -125,6 +137,8 @@ CPU6: cpu@102 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_1>;
> >>> qcom,freq-domain = <&cpufreq_hw 1>;
> >>> + power-domains = <&CPU_PD6>;
> >>> + power-domain-names = "psci";
> >>> };
> >>>
> >>> CPU7: cpu@103 {
> >>> @@ -137,6 +151,8 @@ CPU7: cpu@103 {
> >>> enable-method = "psci";
> >>> next-level-cache = <&L2_1>;
> >>> qcom,freq-domain = <&cpufreq_hw 1>;
> >>> + power-domains = <&CPU_PD7>;
> >>> + power-domain-names = "psci";
> >>> };
> >>>
> >>> cpu-map {
> >>> @@ -176,6 +192,68 @@ core3 {
> >>> };
> >>> };
> >>> };
> >>> +
> >>> + idle-states {
> >>> + entry-method = "psci";
> >>> +
> >>> + LITTLE_CPU_SLEEP_0: cpu-sleep-0-0 {
> >>> + compatible = "arm,idle-state";
> >>> + idle-state-name = "silver-rail-power-collapse";
> >>> + arm,psci-suspend-param = <0x40000003>;
> >>> + entry-latency-us = <290>;
> >>> + exit-latency-us = <376>;
> >>> + min-residency-us = <1182>;
> >>> + local-timer-stop;
> >>> + };
> >>> +
> >>> + BIG_CPU_SLEEP_0: cpu-sleep-1-0 {
> >>> + compatible = "arm,idle-state";
> >>> + idle-state-name = "gold-rail-power-collapse";
> >>> + arm,psci-suspend-param = <0x40000003>;
> >>> + entry-latency-us = <297>;
> >>> + exit-latency-us = <324>;
> >>> + min-residency-us = <1110>;
> >>> + local-timer-stop;
> >>> + };
> >>> + };
> >>> +
> >>> + domain-idle-states {
> >>> + CLUSTER_0_SLEEP_0: cluster-sleep-0-0 {
> >>> + /* GDHS */
> >>> + compatible = "domain-idle-state";
> >>> + arm,psci-suspend-param = <0x40000022>;
> >> This 0x22 ending seems very sus.
> >>
> >> The last nibble represents the core-level power state and the
> >> penultimate one represents the same at cluster level. A value
> >> of 2 in that cluster nibble is actually undefined by the PSCI spec,
> >> whereas the value of 4 (as you have in all of the other idle
> >> states, including D3G for the perf cluster) corresponds to
> >> "Retention", so unless there's a very weird nuance in the
> >> TZ for this SoC, it should probably end in 0x42.
> >>
> >> Otherwise I think this LGTM now!
> >
> > I am also learning by experiment about the exact values to use here,
> > as the only ready reckoner of how these values are calculated, seems
> > to be available via [1].
> >
> > Also it seems the downstream code uses the following approach to
> > calculate the LPM state suspend-param, which for example for
> > CLUSTER_0_SLEEP_1 states turns out to be:
> >
> > state_id = get_cluster_id(cpu->parent, &affinity_level, from_idle); = 0x40
> > power_state = (is-reset << 30) = 0x40000000
> > affinity_level = (affinity level & 0x3) << 24 = 0x1000000
> > state_id += power_state + affinity_level + psci_id;
> >
> > = 0x40000000 + 0x1000000 + 0x40 + 0x4 = 0x41000044
> >
> > For the D3G cases as well, I just used the 'qcom,psci-mode = <2>'
> > value as provided in downstream code (see [2]), for the overall
> > calculations.
> >
> > Also, the only usage of D3G state I could find upstream (in qcom dtsi
> > files0 is for 'msm8916' (see [3]), which also uses the value with
> > ending 0x2 -> 'arm,psci-suspend-param = <0x41000032>'
>
> D3G has min-child-idx = 1, so the end PSCI param should be 0x41000023
> D3 is 0x41000043
Ok, let me recheck at my end as well.
Thanks
Bhupesh