Re: [PATCH 1/2] arm64: dts: qcom: sc7180: Add gpu cooling support

From: Matthias Kaehlcke
Date: Fri Oct 09 2020 - 12:57:09 EST


On Fri, Oct 09, 2020 at 08:05:10AM -0700, Doug Anderson wrote:
> Hi,
>
> On Thu, Oct 8, 2020 at 10:10 AM Akhil P Oommen <akhilpo@xxxxxxxxxxxxxx> wrote:
> >
> > Add cooling-cells property and the cooling maps for the gpu tzones
> > to support GPU cooling.
> >
> > Signed-off-by: Akhil P Oommen <akhilpo@xxxxxxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/qcom/sc7180.dtsi | 29 ++++++++++++++++++++++-------
> > 1 file changed, 22 insertions(+), 7 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> > index d46b383..40d6a28 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> > @@ -2,7 +2,7 @@
> > /*
> > * SC7180 SoC device tree source
> > *
> > - * Copyright (c) 2019, The Linux Foundation. All rights reserved.
> > + * Copyright (c) 2019-20, The Linux Foundation. All rights reserved.
> > */
> >
> > #include <dt-bindings/clock/qcom,dispcc-sc7180.h>
> > @@ -1885,6 +1885,7 @@
> > iommus = <&adreno_smmu 0>;
> > operating-points-v2 = <&gpu_opp_table>;
> > qcom,gmu = <&gmu>;
> > + #cooling-cells = <2>;
>
> Presumably we should add this to the devicetree bindings, too?
>
>
> > interconnects = <&gem_noc MASTER_GFX3D &mc_virt SLAVE_EBI1>;
> > interconnect-names = "gfx-mem";
> > @@ -3825,16 +3826,16 @@
> > };
> >
> > gpuss0-thermal {
> > - polling-delay-passive = <0>;
> > + polling-delay-passive = <100>;
>
> Why did you make this change? I'm pretty sure that we _don't_ want
> this since we're using interrupts for the thermal sensor. See commit
> 22337b91022d ("arm64: dts: qcom: sc7180: Changed polling mode in
> Thermal-zones node").

I was going to ask the same, this shouldn't be needed.

> > polling-delay = <0>;
> >
> > thermal-sensors = <&tsens0 13>;
> >
> > trips {
> > gpuss0_alert0: trip-point0 {
> > - temperature = <90000>;
> > + temperature = <95000>;
> > hysteresis = <2000>;
> > - type = "hot";
> > + type = "passive";
>
> Matthias probably knows better, but I wonder if we should be making
> two passive trip levels like we do with CPU. IIRC this is important
> if someone wants to be able to use this with IPA.

Yes, please introduce a second trip point and make both of them
'passive'.