Index: usb-devel/drivers/usb/core/file.c
===================================================================
--- usb-devel.orig/drivers/usb/core/file.c
+++ usb-devel/drivers/usb/core/file.c
@@ -209,6 +209,8 @@ int usb_register_dev(struct usb_interfac
 		retval = PTR_ERR(intf->usb_dev);
 	}
 	up_write(&minor_rwsem);
+	dev_info(&intf->dev, "Post class create: refcount %d\n",
+			atomic_read(&usb_class->kref.refcount.refs));
 	return retval;
 }
 EXPORT_SYMBOL_GPL(usb_register_dev);
@@ -242,6 +244,8 @@ void usb_deregister_dev(struct usb_inter
 
 	intf->usb_dev = NULL;
 	intf->minor = -1;
+	dev_info(&intf->dev, "Pre class destroy: refcount %d\n",
+			atomic_read(&usb_class->kref.refcount.refs));
 	destroy_usb_class();
 }
 EXPORT_SYMBOL_GPL(usb_deregister_dev);