Re: [PATCH] usb: dwc3: gadget: Propagate core init errors to UDC during pullup

[Thinh Nguyen]

On Thu, Jun 15, 2023, Thinh Nguyen wrote:
> On Wed, Jun 14, 2023, Krishna Kurapati wrote:
> > In scenarios where pullup relies on resume (get sync) to initialize
> > the controller and set the run stop bit, then core_init is followed by
> > gadget_resume which will eventually set run stop bit.
> > 
> > But in cases where the core_init fails, the return value is not sent
> > back to udc appropriately. So according to UDC the controller has
> > started but in reality we never set the run stop bit.
> > 
> > On systems like Android, there are uevents sent to HAL depending on
> > whether the configfs_bind / configfs_disconnect were invoked. In the
> > above mentioned scnenario, if the core init fails, the run stop won't
> > be set and the cable plug-out won't result in generation of any
> > disconnect event and userspace would never get any uevent regarding
> > cable plug out and we never call pullup(0) again. Furthermore none of
> > the next Plug-In/Plug-Out's would be known to configfs.
> > 
> > Return back the appropriate result to UDC to let the userspace/
> > configfs know that the pullup failed so they can take appropriate
> > action.
> > 
> > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> > ---
> >  drivers/usb/dwc3/gadget.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > index 578804dc29ca..27cb671e18e3 100644
> > --- a/drivers/usb/dwc3/gadget.c
> > +++ b/drivers/usb/dwc3/gadget.c
> > @@ -2747,7 +2747,9 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
> >  	ret = pm_runtime_get_sync(dwc->dev);
> >  	if (!ret || ret < 0) {
> >  		pm_runtime_put(dwc->dev);
> > -		return 0;
> > +		if (ret < 0)
> > +			pm_runtime_set_suspended(dwc->dev);
> > +		return ret;
> >  	}
> >  
> >  	if (dwc->pullups_connected == is_on) {
> > -- 
> > 2.40.0
> > 
> 
> Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
> 

I think this patch qualifies as a fix. Can you also add a fixes tag?

Thanks!
Thinh