Re: [PATCH v4 2/2] ARM: dts: qcom: Support Motorola Moto G2 (2014)

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The fixed regulator `vddio_disp_vreg` is missing its `vin-supply` link to `pm8226_l8`, which will cause the display VDDIO to be unpowered after boot.
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commit 70499333aacadd0ef2c646a655f7350a4c0e3f57
Author: David Wales <daviewales@disroot.org>
ARM: dts: qcom: Support Motorola Moto G2 (2014)

This commit adds the initial device tree for the Motorola Moto G2 (2014)
smartphone based on the Qualcomm MSM8226 SoC. It adds support for buttons,
eMMC, a Hall Effect Sensor, simple framebuffer display, and a vibrator.

Link: https://github.com/LineageOS/android_kernel_motorola_msm8226/blob/cm-14.1/Documentation/devicetree/bindings/misc/hob_ram.txt

> diff --git a/arch/arm/boot/dts/qcom/msm8226-motorola-titan.dts b/arch/arm/boot/dts/qcom/msm8226-motorola-titan.dts
> new file mode 100644
> index 0000000000000..1609fb21c5448
> --- /dev/null
> +++ b/arch/arm/boot/dts/qcom/msm8226-motorola-titan.dts

[ ... ]

> +	vddio_disp_vreg: regulator-vddio-disp {
> +		compatible = "regulator-fixed";
> +		regulator-name = "vddio_disp";
> +
> +		gpio = <&tlmm 10 GPIO_ACTIVE_HIGH>;
> +		startup-delay-us = <300>;
> +		enable-active-high;
> +		regulator-boot-on;
> +	};

[Severity: High]
Will this regulator fail to supply power if its upstream source is turned
off?

This fixed regulator controls the display VDDIO power via a GPIO, but it
seems to be missing its vin-supply link to pm8226_l8. Without the
vin-supply property, the regulator core is unaware of the parent-child
dependency, so enabling vddio_disp_vreg won't automatically enable
pm8226_l8.

[ ... ]

> +		pm8226_l8: l8 {
> +			regulator-min-microvolt = <1800000>;
> +			regulator-max-microvolt = <1800000>;
> +		};

[Severity: High]
Will this regulator get disabled by the regulator core during late init?

Because pm8226_l8 is not referenced by vddio_disp_vreg or any other
consumer, and it is not marked regulator-always-on, it appears it will be
disabled as an unused regulator. When this happens, will power to the
display be cut, causing the screen to go blank?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260605-device-motorola-titan-mainline-v4-0-08a7be31f05c@disroot.org?part=2