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

[Faisal Hassan <faisal.hassan@oss.qualcomm.com>]

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@oss.qualcomm.com>
>> ---
>>   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