Re: [PATCH 5/7] arm64: dts: qcom: ideacentre-mini: Fix the second M.2 3V3 rail

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Encoding a consumer (M.2 NVMe) power-up delay into the provider (regulator) DT node as 'startup-delay-us' violates Device Tree design principles.
--

commit 74fe38037d977753f0083d520b231c28126f164d
Author: Jens Glathe <jens.glathe@oldschoolsolutions.biz>

arm64: dts: qcom: ideacentre-mini: Fix the second M.2 3V3 rail

This commit switches the vreg_nvme2_3p3 regulator to the PMIC GPIO and adds a
2-second startup delay along with an always-on property to work around M.2
probing failures.

> diff --git a/arch/arm64/boot/dts/qcom/x1-lenovo-ideacentre-mini-01q8x10.dtsi b/arch/arm64/boot/dts/qcom/x1-lenovo-ideacentre-mini-01q8x10.dtsi
> --- a/arch/arm64/boot/dts/qcom/x1-lenovo-ideacentre-mini-01q8x10.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1-lenovo-ideacentre-mini-01q8x10.dtsi
[ ... ]
> @@ -173,13 +174,16 @@ vreg_nvme2_3p3: regulator-nvme2-3p3 {
>  		regulator-min-microvolt = <3300000>;
>  		regulator-max-microvolt = <3300000>;
>  
> -		gpio = <&tlmm 18 GPIO_ACTIVE_HIGH>;
> +		gpio = <&pmc8380_3_gpios 5 GPIO_ACTIVE_HIGH>;
>  		enable-active-high;
>  
> -		pinctrl-0 = <&nvme_reg_en>;
> +		pinctrl-0 = <&nvme2_reg_en>;
>  		pinctrl-names = "default";
>  
> +		startup-delay-us = <2000000>;

[Severity: Medium]
Does adding startup-delay-us to the regulator node violate Device Tree design
principles by encoding a software workaround for the consumer's (M.2 NVMe)
initialization time?

Device Tree serves as a hardware description and stable ABI. Encoding a
2,000,000 us (2 seconds) delay here describes the consumer's initialization
time, rather than the physical stabilization time of the regulator hardware.

Once a proper M.2 PCIe power sequencer driver is introduced, will this node
continue to force the regulator framework to needlessly block for 2 seconds
whenever the regulator is enabled?

> +
>  		regulator-boot-on;
> +		regulator-always-on;
>  	};
>  
>  	vreg_v0p9: regulator-v0p9 {

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260905-x1-ideacentre-mini-prettify-v1-0-9a87882973bb@oldschoolsolutions.biz?part=5