[2/4] arm64: dts: qcom: msm8996: Pass VDDMX to gpu in power-domains

Message ID 20230329-topic-adreno_opp-v1-2-24d34ac6f007@linaro.org
State New
Headers
Series Improve some Adreno Device Tree nodes |

Commit Message

Konrad Dybcio March 29, 2023, 7:17 p.m. UTC
  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@linaro.org>
---
 arch/arm64/boot/dts/qcom/msm8996.dtsi | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
  

Comments

Dmitry Baryshkov March 29, 2023, 9:29 p.m. UTC | #1
On Wed, 29 Mar 2023 at 22:17, Konrad Dybcio <konrad.dybcio@linaro.org> 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@linaro.org>
> ---
>  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
>
  

Patch

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!
+			 */
+			power-domains = <&mmcc GPU_GX_GDSC>;
 		};
 
 		venus: video-codec@c00000 {