Re: [PATCH] ARM: dts: stm32: lxa: drop unnecessary vusb_d/a-supply

[Alexandre TORGUE <alexandre.torgue@foss.st.com>]

Hi Ahmad

On 10/7/25 07:36, Ahmad Fatoum wrote:
> The LXA device trees are the only STM32MP1 device tree that specify
> vusb_d/usb_a-supply and apparently not for good reason:
> 
> - vusb_d-supply (vdd_usb) is the same as the phy-supply for usbphyc_port1
> - vusb_a-supply (reg18) is the same as vdda1v8-supply for usbphyc_port1
> 
> and usbphyc_port1 is linked to the usbotg_hs node via the phys property.
> 
> Specifying the regulators in the &usbotg_hs node is thus superfluous and
> has been even found to be harmful in one instance:
> Linux v6.10 was found to lock up every 50-125 or so reboots on the LXA
> TAC when the DWC2 driver probe enables the regulators in bulk, unless
> both properties were removed.
> 
> This issue was so far not reproducible on v6.17 (> 500 reboots), but as
> these properties are unnecessary and different from other STM32MP1
> boards, remove them anyway.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>   arch/arm/boot/dts/st/stm32mp153c-lxa-fairytux2.dtsi | 3 ---
>   arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi       | 3 ---
>   2 files changed, 6 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/st/stm32mp153c-lxa-fairytux2.dtsi b/arch/arm/boot/dts/st/stm32mp153c-lxa-fairytux2.dtsi
> index 9eeb9d6b5eb0ed35d4a83b743e8007f19422e2ed..7d3a6a3b5d09ea06689ebca11eda48785207aa31 100644
> --- a/arch/arm/boot/dts/st/stm32mp153c-lxa-fairytux2.dtsi
> +++ b/arch/arm/boot/dts/st/stm32mp153c-lxa-fairytux2.dtsi
> @@ -374,9 +374,6 @@ &usbotg_hs {
>   	phys = <&usbphyc_port1 0>;
>   	phy-names = "usb2-phy";
>   
> -	vusb_d-supply = <&vdd_usb>;
> -	vusb_a-supply = <&reg18>;
> -
>   	status = "okay";
>   };
>   
> diff --git a/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi b/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi
> index be0c355d3105b89d4374d4f6972c7927970f06b1..9179075f2ead14a4deb45fcd2cefd60ab426a8d8 100644
> --- a/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi
> +++ b/arch/arm/boot/dts/st/stm32mp15xc-lxa-tac.dtsi
> @@ -493,9 +493,6 @@ &usbotg_hs {
>   	phys = <&usbphyc_port1 0>;
>   	phy-names = "usb2-phy";
>   
> -	vusb_d-supply = <&vdd_usb>;
> -	vusb_a-supply = <&reg18>;
> -
>   	g-rx-fifo-size = <512>;
>   	g-np-tx-fifo-size = <32>;
>   	g-tx-fifo-size = <128 128 64 16 16 16 16 16>;
> 
> ---
> base-commit: 33f3d92bd1bee0e37d68124dd6e7df793a6af745
> change-id: 20251007-lxa-usb-dt-ceb0189396e6
> 
> Best regards,

Applied on stm32-next.

Cheers.
Alex