Re: [PATCH] arm64: dts: rockchip: Add the GPU to Kobol Helios64

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] arm64: dts: rockchip: missing regulator-initial-mode for vdd_gpu causes panfrost timeouts
--

commit e9e84838a5d23aecac47c2c16bd51c1be53464af
Author: Igor Velkov <iav@iav.lv>

arm64: dts: rockchip: Add the GPU to Kobol Helios64

This commit adds the GPU core description to the Helios64 device tree,
using a silergy,syr828 regulator on i2c0 at 0x41.

> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts b/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts
> index 63ad79b4c8ac3..1f50982291bfe 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts
[ ... ]
> @@ -453,6 +458,25 @@ regulator-state-mem {
>  			regulator-off-in-suspend;
>  		};
>  	};
> +
> +	vdd_gpu: regulator@41 {
> +		compatible = "silergy,syr828";
> +		reg = <0x41>;
> +		fcs,suspend-voltage-selector = <1>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&vsel2_pin>;

[Severity: High]
Does this regulator definition need regulator-initial-mode = <1>; to force
PWM mode?

Without forcing PWM mode on the SYR828 regulator, sudden GPU current demands
cause transient voltage droops that lead to Panfrost job timeouts. 

The vdd_gpu regulator uses silergy,syr828, which is handled by the fan53555
regulator driver. Without regulator-initial-mode = <1>;, the regulator
remains in its default Auto (PFM/PWM) mode, which cannot respond fast
enough to large current spikes during active GPU workloads.

Adding regulator-initial-mode = <1>; forces the regulator into fast PWM mode
(REGULATOR_MODE_FAST), preventing the voltage droops and resulting job
timeouts.

> +		regulator-name = "vdd_gpu";
> +		regulator-always-on;
> +		regulator-boot-on;
> +		regulator-min-microvolt = <712500>;
> +		regulator-max-microvolt = <1500000>;
> +		regulator-ramp-delay = <1000>;
> +		vin-supply = <&vcc5v0_sys>;
> +
> +		regulator-state-mem {
> +			regulator-off-in-suspend;
> +		};
> +	};
>  };
>

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261011-b4-helios64-gpu-v1-1-bd83c6ecd19e@iav.lv?part=1