Re: [PATCH 1/3] arm64: dts: rockchip: Enable USB 2.0 host1 on Radxa ROCK 3B

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] dts: false 5V VBUS dependency for M.2 WWAN slot
--

commit 87931f73c3a7da52681aaf73a831d1638bf48ff3
Author: Adam Wermuth <adam@wermuth.pl>

arm64: dts: rockchip: Enable USB 2.0 host1 on Radxa ROCK 3B

This commit routes the USB 2.0 data lines of the M.2 B-key slot to USB2_HOST3
by enabling the ehci/ohci controllers and the usb2phy1 host port, allowing
LTE modems and other modules to enumerate.

> diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
> index 149a5306bb032..ad9a91c0d0d0e 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3b.dts

[ ... ]

> @@ -780,6 +788,11 @@ &usb2phy1 {
>  	status = "okay";
>  };
>  
> +&usb2phy1_host {
> +	phy-supply = <&vcc5v0_usb_host>;

[Severity: Medium]
Does this create a false 5V VBUS dependency for the M.2 WWAN slot?

The M.2 specification dictates 3.3V power and no VBUS pin. By associating the
5V external Type-A VBUS regulator (vcc5v0_usb_host) with the M.2 slot's PHY
here, the PHY core will automatically enable this regulator when initialized.

Will this force the 5V rail to remain active as long as the M.2 LTE modem's
USB PHY is active, leading to unnecessary power consumption even when external
ports are unused?

> +	status = "okay";
> +};
> +
>  &usb2phy1_otg {
>  	phy-supply = <&vcc5v0_usb_host>;
>  	status = "okay";

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260924071445.441822-1-adam@wermuth.pl?part=1