Re: [PATCH v2 1/2] usb: dwc3: gadget: Avoid controller stop in .suspend if !softconnect

Roger Quadros
2023-05-03T09:28:48Z

On 03/05/2023 00:17, Thinh Nguyen wrote:
> On Tue, May 02, 2023, Roger Quadros wrote:
>> If softconnect is not set it means the controller has not started,
>> so no point in stopping it in dwc3_gadget_suspend()
>>
>> Cc: stable@vger.kernel.org # 5.16
>> Fixes: 8217f07a5023 ("usb: dwc3: gadget: Avoid starting DWC3 gadget during UDC unbind")
>
> If the reason for this patch is as mentioned in the commit message, then
> I don't think this is a fix patch that needs to be backported to stable.
> The reason why we needed to check both dwc->gadget_driver and
> dwc->softconnect is because of a potential race between resume and
> unbind. Would there be a similar case in dwc_gadget_suspend where a
> potential race may occur? If not, I don't think we need this patch.

OK. I agree.

>
> Thanks,
> Thinh
>
>> Signed-off-by: Roger Quadros <rogerq@kernel.org>
>> ---
>> drivers/usb/dwc3/gadget.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index c0ca4d12f95d..b5170374cd18 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -4656,7 +4656,7 @@ int dwc3_gadget_suspend(struct dwc3 *dwc)
>> {
>> unsigned long flags;
>>
>> - if (!dwc->gadget_driver)
>> + if (!dwc->gadget_driver || !dwc->softconnect)
>> return 0;
>>
>> dwc3_gadget_run_stop(dwc, false);
>> --
>> 2.34.1

cheers,
-roger