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SubjectRe: [PATCH] arm64: dts: qcom: qcs404: Add PSCI cpuidle support
On Wed, May 08, 2019 at 02:48:19AM +0530, Amit Kucheria wrote:
> On Tue, May 7, 2019 at 1:01 AM Niklas Cassel <niklas.cassel@linaro.org> wrote:
> >
> > Add device bindings for CPUs to suspend using PSCI as the enable-method.
> >
> > Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
> > ---
> > arch/arm64/boot/dts/qcom/qcs404.dtsi | 15 +++++++++++++++
> > 1 file changed, 15 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/qcs404.dtsi b/arch/arm64/boot/dts/qcom/qcs404.dtsi
> > index ffedf9640af7..f9db9f3ee10c 100644
> > --- a/arch/arm64/boot/dts/qcom/qcs404.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/qcs404.dtsi
> > @@ -31,6 +31,7 @@
> > reg = <0x100>;
> > enable-method = "psci";
> > next-level-cache = <&L2_0>;
> > + cpu-idle-states = <&CPU_PC>;
> > };
> >
> > CPU1: cpu@101 {
> > @@ -39,6 +40,7 @@
> > reg = <0x101>;
> > enable-method = "psci";
> > next-level-cache = <&L2_0>;
> > + cpu-idle-states = <&CPU_PC>;
> > };
> >
> > CPU2: cpu@102 {
> > @@ -47,6 +49,7 @@
> > reg = <0x102>;
> > enable-method = "psci";
> > next-level-cache = <&L2_0>;
> > + cpu-idle-states = <&CPU_PC>;
> > };
> >
> > CPU3: cpu@103 {
> > @@ -55,12 +58,24 @@
> > reg = <0x103>;
> > enable-method = "psci";
> > next-level-cache = <&L2_0>;
> > + cpu-idle-states = <&CPU_PC>;
> > };
> >
> > L2_0: l2-cache {
> > compatible = "cache";
> > cache-level = <2>;
> > };
> > +
> > + idle-states {
>
> entry-method="psci" property goes here. I have a patch fixing it for 410c ;-)
>
> I don't think the psci_cpuidle_ops will even get called without this.

Hello Amit,

I added debug prints in psci_cpu_suspend_enter() and arm_cpuidle_suspend()
when verifying this patch, and psci_cpu_suspend_enter() is indeed called,
with the correct psci suspend parameter.

The output from:
grep "" /sys/bus/cpu/devices/cpu0/cpuidle/state?/*
also looks sane.

However, if 'entry-method="psci"' is required according to the DT binding,
perhaps you can send a 2/2 series that fixes both this patch and msm8916 ?

> Did you see any changes in consumption with this patch? I was trying
> to measure that before sending this out.

I don't know of any way to measure the power consumption on this board,
so no, I haven't been able to verify that the firmware actually does
the right thing here.


Kind regards,
Niklas

>
> > + CPU_PC: pc {
> > + compatible = "arm,idle-state";
> > + arm,psci-suspend-param = <0x40000003>;
> > + entry-latency-us = <125>;
> > + exit-latency-us = <180>;
> > + min-residency-us = <595>;
> > + local-timer-stop;
> > + };
> > + };
> > };
> >
> > firmware {
> > --
> > 2.21.0
> >

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