Re: [PATCH v2] arm64: dts: qcom: sc7280: Add capacity and DPC properties

[Konrad Dybcio]

On 11/6/23 17:56, Doug Anderson wrote:
> Hi,
>
> On Sat, Nov 4, 2023 at 4:52 AM Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote:
> > On 11/3/23 11:54, Ankit Sharma wrote:
> > > The "capacity-dmips-mhz" and "dynamic-power-coefficient" are
> > > used to build Energy Model which in turn is used by EAS to take
> > > placement decisions. So add it to SC7280 soc.
> > >
> > > Signed-off-by: Ankit Sharma <quic_anshar@xxxxxxxxxxx>
> > > ---Hi, thanks for this patch
> >
> > Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> >
> > I performed a quick grep in arch/arm64/boot/dts/qcom and noticed
> > that at least one of these values is missing for:
> >
> > rg -l --files-without-match dynamic-power-coeff $(rg cpu@ -l) | sort
> > ipq5018.dtsi (homogeneous cluster)
> > ipq5332.dtsi (homogeneous cluster)
> > ipq6018.dtsi (homogeneous cluster)
> > ipq8074.dtsi (homogeneous cluster)
> > ipq9574.dtsi (homogeneous cluster)
> > msm8916.dtsi (homogeneous cluster)
> > msm8939.dtsi
> > msm8953.dtsi
> > msm8976.dtsi
> > msm8994.dtsi
> > msm8996.dtsi
> > msm8998.dtsi
> > qcs404.dtsi (homogeneous cluster)
> > qdu1000.dtsi (homogeneous cluster)
> > sa8775p.dtsi
> > sc7280.dtsi
> > sc8180x.dtsi
> > sc8280xp.dtsi
> > sdm630.dtsi
> > sm4450.dtsi
> > sm6125.dtsi
> > sm6375.dtsi
> > sm8350.dtsi
> > sm8450.dtsi
> >
> > rg -l --files-without-match capacity-dmips $(rg cpu@ -l) | sort
> > ipq5018.dtsi (homogeneous cluster)
> > ipq5332.dtsi (homogeneous cluster)
> > ipq6018.dtsi (homogeneous cluster)
> > ipq8074.dtsi (homogeneous cluster)
> > ipq9574.dtsi (homogeneous cluster)
> > msm8916.dtsi (homogeneous cluster)
> > msm8939.dtsi
> > msm8994.dtsi
> > qcs404.dtsi (homogeneous cluster)
> > qdu1000.dtsi (homogeneous cluster)
> > sa8775p.dtsi
> > sc7280.dtsi
> > sm4450.dtsi
> > sm6375.dtsi
> > sm8350.dtsi
> > sm8450.dtsi
> >
> > Where platforms with a single, homogeneous cluster likely don't
> > benefit from EAS..
> >
> > Is there any chance you could dig up the correct values, for at least
> > some of these platforms? Or would you know whom to ask?
> >
> > FWIW the one we're missing the most is sc8280xp..
>
> FWIW, I wrote up a longwinded commit message when I added these values
> for sc7180. See commit 82ea7d411d43 ("arm64: dts: qcom: sc7180: Base
> dynamic CPU power coefficients in reality").
>
> The short of it is that if you have hardware and a basic "smart
> battery" to measure power consumption it's pretty easy for anyone to
> add some reasonable numbers.
That's a big ask, especially with stupid laptop battmgr firmware that
only refreshes data every 5 to 25 seconds :)

Qcom probably has some reasonable numbers somewhere, given they are
likely to test their SoCs' characteristics before taping them out
en masse :P

Konrad