On Wed, 29 Mar 2023 at 22:17, Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote:
>
> Since power-domains is used for perf_level pm_genpd scaling, it's only
> fitting that we pass a power domain that's actually supposed to be
> scaled (and not only turned on/off) to the GPU. While we don't quite
> support CPR3 yet, the next best thing we can do is pass VDDMX, so that
> we're at least guaranteed a reasonable vote on the memory side of
> things. Do so and leave a note mentioning CPR3 PD should be used here
> instead when support is added.
>
> Fixes: 69cc3114ab0f ("arm64: dts: Add Adreno GPU definitions")
> Fixes: 3f65d51e9e22 ("arm64: dts: qcom: msm8996: Make GPU node control GPU_GX GDSC")
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> ---
> arch/arm64/boot/dts/qcom/msm8996.dtsi | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
> index 4661a556772e..4dd37f72e018 100644
> --- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
> +++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
> @@ -1228,7 +1228,8 @@ gpu: gpu@b00000 {
> interconnects = <&bimc MASTER_GRAPHICS_3D &bimc SLAVE_EBI_CH0>;
> interconnect-names = "gfx-mem";
>
> - power-domains = <&mmcc GPU_GX_GDSC>;
> + /* TODO: also scale VDDGFX with CPR3 */
> + power-domains = <&rpmpd MSM8996_VDDMX>;
> iommus = <&adreno_smmu 0>;
>
> nvmem-cells = <&speedbin_efuse>;
> @@ -2254,7 +2255,13 @@ adreno_smmu: iommu@b40000 {
> <&mmcc GPU_AHB_CLK>;
> clock-names = "bus", "iface";
>
> - power-domains = <&mmcc GPU_GDSC>;
> + /*
> + * We need both GPU_GDSC and GPU_GX_GDSC to be on, but the
> + * power-domains entry under gpu is occupied by the scaled
> + * voltage domain. Since GPU_GDSC is a parent of GX_GDSC,
> + * we can simply pass GX here to turn them both on!
> + */
Ugh. You can pass GX and VDDMX to the gpu. Let me send the patch
supporting that.
> + power-domains = <&mmcc GPU_GX_GDSC>;
> };
>
> venus: video-codec@c00000 {
>
> --
> 2.40.0
>
--
With best wishes
Dmitry
