On Thu 02 Apr 01:13 PDT 2020, Stephan Gerhold wrote: > Hi, > > On Wed, Apr 01, 2020 at 07:50:59PM +0200, Loic Poulain wrote: > > The highest cpu frequency opps have been dropped because CPR is not > > supported. However, we can simply specify operating voltage so that > > they match the max corner voltages for each freq. With that, we can > > support up to 1.36Ghz. Ideally, msm8916 CPR should be implemented to > > fine tune operating voltages and optimize power consumption. > > Thanks for the patch! I was wondering how to enable the higher CPU > frequencies for a while now... > > I was actually quite excited to see CPR being mainlined for QCS404. > If we are trying to add such a workaround (rather than CPR) for MSM8916 > now, does that mean it's unlikely to see CPR working for MSM8916 > anytime soon? > > AFAICT, there is a WIP branch from Niklas Cassel here: > https://git.linaro.org/people/nicolas.dechesne/niklas.cassel/kernel.git/log/?h=cpr-msm8916-mainline > but it hasn't been updated for a while. (Not sure if it was working > already...) > > Can someone explain what is missing to make CPR work for MSM8916? > CPR needs to control 3 things; VDD_APC, VDD_MX and MEMACC. On QCS404 it seems we don't have to adjust VDD_MX, so the code for this is missing from the driver. So, afaict, what's missing is that rpmpd.c needs to gain support for 8916, then the CPR driver needs to gain a cpr_acc_desc and compatible for 8916, it needs to reference the VDDMX power domain and before/after we're adjusting the corner of the CPR we need to adjust the MX according to the mapping specified in the downstream kernel (i.e. 1->4, 2->5 and 3->7). Unfortunately, the requirement that VDDMX (VDD_MEM I presume) must be higher than VDD_APC most likely needs to be taken into consideration for Loic's proposed static voltage scaling as well. Unless VDD_MEM is left in Turbo mode from the boot loader I think we need to take VDDMX to corner 7 for speeds 998MHz and above (i.e. where we pull VDD_APC to 1.35V). Regards, Bjorn > One other minor comment/question below. > > > > > This patch: > > - Adds missing opps and corresponding target voltages to msm8916.dtsi. > > - Adds cpu-supply to apq8016-sbc.dtsi (board level info). > > - Adds pm8916 spmi regulator node to pm8916.dtsi. > > > > Tested with a dragonboard-410c. > > > > Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx> > > --- > > arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi | 24 ++++++++++++++++++++++++ > > arch/arm64/boot/dts/qcom/msm8916.dtsi | 24 ++++++++++++++++++++++++ > > arch/arm64/boot/dts/qcom/pm8916.dtsi | 6 ++++++ > > 3 files changed, 54 insertions(+) > > > > diff --git a/arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi b/arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi > > index 037e26b..f1c1216 100644 > > --- a/arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi > > +++ b/arch/arm64/boot/dts/qcom/apq8016-sbc.dtsi > > @@ -560,6 +560,30 @@ > > qcom,mbhc-vthreshold-high = <75 150 237 450 500>; > > }; > > > > +&spm_regulators { > > + vdd_cpu: s2 { > > + regulator-always-on; > > + regulator-min-microvolt = <1050000>; > > + regulator-max-microvolt = <1350000>; > > + }; > > +}; > > + > > +&CPU0 { > > + cpu-supply = <&vdd_cpu>; > > +}; > > + > > +&CPU1 { > > + cpu-supply = <&vdd_cpu>; > > +}; > > + > > +&CPU2 { > > + cpu-supply = <&vdd_cpu>; > > +}; > > + > > +&CPU3 { > > + cpu-supply = <&vdd_cpu>; > > +}; > > + > > I'm a bit confused about the separation here. The cpu-supply is defined > in the board-specific device tree, yet the voltages are set in the > common device tree below. > > Is it even possible that the CPU is supplied by something other than S2 > and if yes, how likely is this? > > I'm asking because I have two other MSM8916 devices in mainline > (and a few more pending upstreaming), and it seems like I would need to > duplicate this into each of them. > > Thanks, > Stephan > > > &smd_rpm_regulators { > > vdd_l1_l2_l3-supply = <&pm8916_s3>; > > vdd_l5-supply = <&pm8916_s3>; > > diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi > > index 9f31064..9805af0 100644 > > --- a/arch/arm64/boot/dts/qcom/msm8916.dtsi > > +++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi > > @@ -342,15 +342,39 @@ > > > > opp-200000000 { > > opp-hz = /bits/ 64 <200000000>; > > + opp-microvolt = <1050000>; > > }; > > opp-400000000 { > > opp-hz = /bits/ 64 <400000000>; > > + opp-microvolt = <1050000>; > > + }; > > + opp-533330000 { > > + opp-hz = /bits/ 64 <533330000>; > > + opp-microvolt = <1150000>; > > }; > > opp-800000000 { > > opp-hz = /bits/ 64 <800000000>; > > + opp-microvolt = <1150000>; > > }; > > opp-998400000 { > > opp-hz = /bits/ 64 <998400000>; > > + opp-microvolt = <1350000>; > > + }; > > + opp-1094400000 { > > + opp-hz = /bits/ 64 <1094400000>; > > + opp-microvolt = <1350000>; > > + }; > > + opp-1152000000 { > > + opp-hz = /bits/ 64 <1152000000>; > > + opp-microvolt = <1350000>; > > + }; > > + opp-1209600000 { > > + opp-hz = /bits/ 64 <1209600000>; > > + opp-microvolt = <1350000>; > > + }; > > + opp-1363200000 { > > + opp-hz = /bits/ 64 <1363200000>; > > + opp-microvolt = <1350000>; > > }; > > }; > > > > diff --git a/arch/arm64/boot/dts/qcom/pm8916.dtsi b/arch/arm64/boot/dts/qcom/pm8916.dtsi > > index 0bcdf04..c9b9c4f 100644 > > --- a/arch/arm64/boot/dts/qcom/pm8916.dtsi > > +++ b/arch/arm64/boot/dts/qcom/pm8916.dtsi > > @@ -157,5 +157,11 @@ > > vdd-micbias-supply = <&pm8916_l13>; > > #sound-dai-cells = <1>; > > }; > > + > > + spm_regulators: spm_regulators { > > + compatible = "qcom,pm8916-regulators"; > > + #address-cells = <1>; > > + #size-cells = <1>; > > + }; > > }; > > }; > > -- > > 2.7.4 > >
