Re: [PATCH v2 2/2] usb: gadget: udc: Handle gadget_connect failure during bind operation

[Alan Stern]

On Wed, Apr 26, 2023 at 06:47:13AM +0530, Krishna Kurapati PSSNV wrote:
> Hi Alan, Geert,
> 
>  Can you help review and provide comments/approval on the following patch.
> 
> Regards,
> Krishna,

Sorry this took so long to review; I've been quite busy.

The patch is good except for one stylistic thing...

> On 3/28/2023 9:37 PM, Krishna Kurapati wrote:
> > In the event, gadget_connect call (which invokes pullup) fails,
> > propagate the error to udc bind operation which inturn sends the
> > error to configfs. The userspace can then retry enumeartion if
> > it chooses to.
> > 
> > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> > ---
> >   drivers/usb/gadget/udc/core.c | 20 ++++++++++++++++----
> >   1 file changed, 16 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> > index 23b0629a8774..975205a1853f 100644
> > --- a/drivers/usb/gadget/udc/core.c
> > +++ b/drivers/usb/gadget/udc/core.c
> > @@ -1051,12 +1051,16 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state);
> >   /* ------------------------------------------------------------------------- */
> > -static void usb_udc_connect_control(struct usb_udc *udc)
> > +static int usb_udc_connect_control(struct usb_udc *udc)
> >   {
> > +	int ret;
> > +
> >   	if (udc->vbus)
> > -		usb_gadget_connect(udc->gadget);
> > +		ret = usb_gadget_connect(udc->gadget);
> >   	else
> > -		usb_gadget_disconnect(udc->gadget);
> > +		ret = usb_gadget_disconnect(udc->gadget);
> > +
> > +	return ret;
> >   }
> >   /**
> > @@ -1500,11 +1504,19 @@ static int gadget_bind_driver(struct device *dev)
> >   	if (ret)
> >   		goto err_start;
> >   	usb_gadget_enable_async_callbacks(udc);
> > -	usb_udc_connect_control(udc);
> > +	ret = usb_udc_connect_control(udc);
> > +	if (ret)
> > +		goto err_connect_control;
> >   	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
> >   	return 0;
> > + err_connect_control:

For consistency with the other error-handling statement labels in this 
routine, there should be a blank line immediately before this label.

> > +	usb_gadget_disable_async_callbacks(udc);
> > +	if (gadget->irq)
> > +		synchronize_irq(gadget->irq);
> > +	usb_gadget_udc_stop(udc);
> > +
> >    err_start:
> >   	driver->unbind(udc->gadget);

Everything else looks okay.

Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

Alan Stern