Re: [PATCH V4 7/7] arm64: dts: imx95: Move power supply properties to Root Port node

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Removing legacy power supply properties from the PCIe controller nodes breaks backwards compatibility for older kernels booting with the updated Device Tree.
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commit 332f451afbc5374b9f81acdbad51ee15f1b90088
Author: Sherry Sun <sherry.sun@nxp.com>

arm64: dts: imx95: Move power supply properties to Root Port node

This commit moves power supply properties from the PCIe controller nodes to
the Root Port child nodes. This change is made to support the new PCI
pwrctrl framework.

> diff --git a/arch/arm64/boot/dts/freescale/imx95-15x15-evk.dts b/arch/arm64/boot/dts/freescale/imx95-15x15-evk.dts
> index 7d820a0f80b22..6aedcbbe915a5 100644
> --- a/arch/arm64/boot/dts/freescale/imx95-15x15-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx95-15x15-evk.dts
> @@ -555,8 +555,6 @@ &pcie0 {
>  	pinctrl-names = "default";
>  	/* This property is deprecated, use reset-gpios from the Root Port node. */
>  	reset-gpio = <&gpio5 13 GPIO_ACTIVE_LOW>;
> -	vpcie-supply = <&reg_m2_pwr>;
> -	vpcie3v3aux-supply = <&reg_m2_pwr>;

[Severity: High]
Does removing these legacy power supply properties break backwards
compatibility for older kernels booting with this updated Device Tree?

Since older kernels lack the pwrctrl framework to handle the new Root Port
properties, they rely on finding vpcie-supply and vpcie3v3aux-supply in the
PCIe host node. Without them, the legacy pci-imx6 driver silently skips
enabling the power regulators, and PCIe initialization will fail because the
slot remains unpowered.

The reset-gpio property was intentionally left to preserve backward
compatibility, but removing the power supplies appears to defeat that
effort. Keeping the legacy regulator properties (even if marked as
deprecated) should be safe, as the kernel regulator framework uses reference
counting and allows both the legacy driver and the new pwrctrl framework to
concurrently enable the same regulator without conflict.

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260630060710.3294811-1-sherry.sun@oss.nxp.com?part=7