Re: [PATCH v4 7/7] usb: dwc3: qcom: Enable VBUS override at probe for default peripheral role

[Faisal Hassan]

On 02-11-2026 12:06 pm, Peter Chen wrote:
> On 26-10-29 00:29:37, Faisal Hassan wrote:
> > When the controller is in OTG mode with usb-role-switch and
> > role-switch-default-mode set to peripheral, the role notifier never sees
> > a transition at probe, so the QSCRATCH VBUS override is not programmed
> > and the device never gets a session-valid indication.
> >
> > Enable the VBUS override at probe whenever the initial role is
> > USB_ROLE_DEVICE.
> >
> > Validated on SA8255P with an HS host attached: 20 unbind/bind and 20
> > suspend/resume iterations completed with no failures.
> >
> > Signed-off-by: Faisal Hassan <faisal.hassan@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/usb/dwc3/dwc3-qcom.c | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > index 0896a323bdda..92f1223f7b21 100644
> > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > @@ -953,10 +953,12 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
> >   		dwc3_qcom_vbus_override_enable(qcom, true);
>
> ....
>
> >   	} else {
> >   		if ((device_property_read_bool(dev, "usb-role-switch")) &&
> > -		    (usb_get_role_switch_default_mode(dev) == USB_DR_MODE_HOST))
> > +		    (usb_get_role_switch_default_mode(dev) == USB_DR_MODE_HOST)) {
> >   			qcom->current_role = USB_ROLE_HOST;
> > -		else
> > +		} else {
> >   			qcom->current_role = USB_ROLE_DEVICE;
> > +			dwc3_qcom_vbus_override_enable(qcom, true);
> > +		}

Hi Peter,

Thanks for the review.
> How about move it and above [....] under device role, let above code purely determine current_role:
> 	if (qcom->current_role == USB_ROLE_DEVICE)
> 		dwc3_qcom_vbus_override_enable(qcom, true);
>
> Peter

Ok, I will make the mode and role-switch code only determine 
current_role, and enable the VBUS override once afterwards when 
current_role is USB_ROLE_DEVICE.

Thanks,
Faisal