usb: gadget: udc: Handle gadget_connect failure during bind operation

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 <[e-mail]>
Acked-by: Alan Stern <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/gadget/udc/core.c

···
 /* ------------------------------------------------------------------------- */
 
 /* Acquire connect_lock before calling this function. */
-static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock)
+static int usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock)
 {
+	int ret;
+
 	if (udc->vbus && udc->started)
-		usb_gadget_connect_locked(udc->gadget);
+		ret = usb_gadget_connect_locked(udc->gadget);
 	else
-		usb_gadget_disconnect_locked(udc->gadget);
+		ret = usb_gadget_disconnect_locked(udc->gadget);
+
+	return ret;
 }
 
 /**
···
 		goto err_start;
 	}
 	usb_gadget_enable_async_callbacks(udc);
-	usb_udc_connect_control_locked(udc);
+	ret = usb_udc_connect_control_locked(udc);
+	if (ret)
+		goto err_connect_control;
+
 	mutex_unlock(&udc->connect_lock);
 
 	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 	return 0;
+
+ err_connect_control:
+	usb_gadget_disable_async_callbacks(udc);
+	if (gadget->irq)
+		synchronize_irq(gadget->irq);
+	usb_gadget_udc_stop_locked(udc);
 
  err_start:
 	driver->unbind(udc->gadget);