Re: [PATCH 02/11] arm64: dts: qcom: sc8280xp-arcata: Enable backlight

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The eDP backlight regulator (`vreg_edp_bl`) is mapped to the wrong PMIC for its enable GPIO, directly contradicting the hardware findings documented in the commit message.
--

commit 5bb21a2e354ddc1fbe2cb4a72c610f631fc3961f
Author: Jérôme de Bretagne <jerome.debretagne@gmail.com>

arm64: dts: qcom: sc8280xp-arcata: Enable backlight

This commit adds backlight nodes and enables the backlight so that it can be
controlled with the buttons on Surface Pro Type Cover keyboards. The nodes
are similar to the ThinkPad X13s but use a different enable GPIO for the
vreg_edp_bl node.

> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-microsoft-arcata.dts b/arch/arm64/boot/dts/qcom/sc8280xp-microsoft-arcata.dts
> index f2b4470d4407f..14287092fb07e 100644
> --- a/arch/arm64/boot/dts/qcom/sc8280xp-microsoft-arcata.dts
> +++ b/arch/arm64/boot/dts/qcom/sc8280xp-microsoft-arcata.dts
[ ... ]
> @@ -127,6 +137,22 @@ pmic_glink_con1_sbu: endpoint {
>  		};
>  	};
>  
> +	vreg_edp_bl: regulator-edp-bl {
> +		compatible = "regulator-fixed";
> +
> +		regulator-name = "VREG_EDP_BL";
> +		regulator-min-microvolt = <3600000>;
> +		regulator-max-microvolt = <3600000>;
> +
> +		gpio = <&pmc8280c_gpios 6 GPIO_ACTIVE_HIGH>;

[Severity: High]
Does this map to the correct PMIC for the enable GPIO?

The commit message explicitly states that the hardware match for the backlight
enable GPIO was found at platform/c440000.spmi:pmic@3:gpio@8800 (which is
gpio6).

According to sc8280xp-pmics.dtsi, pmic@3 corresponds to the pmc8280_2 PMIC and
its pmc8280_2_gpios controller.

However, the patch configures the regulator and pinctrl to use pmc8280c_gpios,
which is physically mapped to pmic@2.

Will this result in toggling the wrong physical pin on pmic@2 instead of
enabling the eDP backlight?

A review of the remainder of the patch series indicates this misconfiguration
is not fixed in subsequent commits.

> +		enable-active-high;
> +
> +		pinctrl-0 = <&edp_bl_reg_en>;
> +		pinctrl-names = "default";
> +
> +		regulator-boot-on;
> +	};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260520-surface-sp9-5g-for-next-v1-0-9df52552bf87@gmail.com?part=2