[PATCH] phy: renesas: rcar-gen3-usb2: Ignore missing VBUS regulator

[Lad, Prabhakar]

Hi All,

On Thu, Jul 2, 2026 at 1:59 PM Prabhakar <prabhakar.csengg at gmail.com> wrote:
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
>
> Commit b6d7dd157763 ("phy: renesas: rcar-gen3-usb2: Add regulator for
> OTG VBUS control") introduced support for controlling OTG VBUS through
> the regulator framework.
>
> As part of this change, the driver started requesting an exclusive "vbus"
> regulator for OTG-capable PHYs with no_adp_ctrl set. The lookup failure
> was propagated unconditionally, causing probe to fail on platforms where
> no VBUS regulator is described.
>
> On RZ/V2H and RZ/V2N, which do not use a VBUS regulator, this results
> in the following error:
>
>     phy_rcar_gen3_usb2 15800200.usb-phy:
>     dummy supplies not allowed for exclusive requests (id=vbus)
>
> This failure completely prevents the USB 2.0 interface from initializing.
>
> Fix this by allowing the probe to continue if an external VBUS regulator
> is missing. Only propagate the error if the internal vbus-regulator node
> is explicitly present, or if the lookup returns -EPROBE_DEFER. For all
> other missing regulator errors, gracefully assume no external VBUS
> regulator is available and return 0.
>
> Fixes: b6d7dd157763 ("phy: renesas: rcar-gen3-usb2: Add regulator for OTG VBUS control")
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
> ---
>  drivers/phy/renesas/phy-rcar-gen3-usb2.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
>
Note, this patch applies on top of patch [0].

[0] https://lore.kernel.org/all/20260616104459.410743-9-biju.das.jz@bp.renesas.com/

Cheers,
Prabhakar