[PATCH 5/6] arm64: dts: mediatek: mt8188: Move vdec1 power domain under vdec0

[AngeloGioacchino Del Regno]

Il 25/09/24 12:57, Fei Shao ha scritto:
> There are two hardware IP blocks in MT8188 video decoder pipeline:
> vdec-lat and vdec-core, which are powered by vdec0 and vdec1 power
> domains respectively.
> 
> We noticed that vdec-core needs to be powered down before vdec-lat
> during suspend to prevent failures. It's unclear if it's an intended
> hardware design or due to power isolation glitch. But in any case, we
> observed a power-off sequence here, and it can be considered as an
> indirect dependency implication between the vdec0 and vdec1 domains.
> 
> Given that, update vdec1 as a sub-domain of vdec0 to enforce the
> sequence. Also, use more specific clock names for both power domains.
> 

As far as I know, yes, there is a sequence:
  - Cores (mtk-vcodec-core) gets suspended first
  - Then the LATs gets suspended (mtk-vcodec-lat)
  - Finally, the LAT SoC gets suspended (mtk-vcodec-lat-soc)

...but you checked that downstream, and your downstream misses the lat-soc HW
instance, and only has the lat one.

Are you sure that this is not the reason why you're getting this issue? :-)

Otherwise, I feel like we must ask for some clarification from MediaTek, as
I'm mostly sure that the two cores are independent from each other (but I
might, of course, be wrong!).

Cheers,
Angelo

> Signed-off-by: Fei Shao <fshao at chromium.org>
> ---
> 
>   arch/arm64/boot/dts/mediatek/mt8188.dtsi | 22 ++++++++++++----------
>   1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/mediatek/mt8188.dtsi b/arch/arm64/boot/dts/mediatek/mt8188.dtsi
> index ff5c8e0597f9..a6cd08ea74eb 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8188.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8188.dtsi
> @@ -1064,20 +1064,22 @@ power-domain at MT8188_POWER_DOMAIN_VPPSYS1 {
>   							#power-domain-cells = <0>;
>   						};
>   
> -						power-domain at MT8188_POWER_DOMAIN_VDEC1 {
> -							reg = <MT8188_POWER_DOMAIN_VDEC1>;
> -							clocks = <&vdecsys CLK_VDEC2_LARB1>;
> -							clock-names = "ss-vdec";
> -							mediatek,infracfg = <&infracfg_ao>;
> -							#power-domain-cells = <0>;
> -						};
> -
>   						power-domain at MT8188_POWER_DOMAIN_VDEC0 {
>   							reg = <MT8188_POWER_DOMAIN_VDEC0>;
>   							clocks = <&vdecsys_soc CLK_VDEC1_SOC_LARB1>;
> -							clock-names = "ss-vdec";
> +							clock-names = "ss-vdec1-soc-l1";
>   							mediatek,infracfg = <&infracfg_ao>;
> -							#power-domain-cells = <0>;
> +							#address-cells = <1>;
> +							#size-cells = <0>;
> +							#power-domain-cells = <1>;
> +
> +							power-domain at MT8188_POWER_DOMAIN_VDEC1 {
> +								reg = <MT8188_POWER_DOMAIN_VDEC1>;
> +								clocks = <&vdecsys CLK_VDEC2_LARB1>;
> +								clock-names = "ss-vdec2-l1";
> +								mediatek,infracfg = <&infracfg_ao>;
> +								#power-domain-cells = <0>;
> +							};
>   						};
>   
>   						cam_vcore: power-domain at MT8188_POWER_DOMAIN_CAM_VCORE {