USB: dummy_hcd: don't register drivers on the platform bus

This patch (as1017) makes dummy_hcd behave more like the other USB
peripheral controller drivers by no longer registering its
gadget driver on the platform bus.  Doing that has always been a
mistake, since a usb_gadget_driver isn't a platform_driver.  Instead
the gadget driver is left unregistered in sysfs.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/dummy_hcd.c

@@ -772,18 +772,17 @@ usb_gadget_register_driver (struct usb_gadget_driver *driver)
 	list_del_init (&dum->ep [0].ep.ep_list);
 	INIT_LIST_HEAD(&dum->fifo_req.queue);
 
+	driver->driver.bus = NULL;
 	dum->driver = driver;
 	dum->gadget.dev.driver = &driver->driver;
 	dev_dbg (udc_dev(dum), "binding gadget driver '%s'\n",
 			driver->driver.name);
-	if ((retval = driver->bind (&dum->gadget)) != 0)
-		goto err_bind_gadget;
-
-	driver->driver.bus = dum->gadget.dev.parent->bus;
-	if ((retval = driver_register (&driver->driver)) != 0)
-		goto err_register;
-	if ((retval = device_bind_driver (&dum->gadget.dev)) != 0)
-		goto err_bind_driver;
+	retval = driver->bind(&dum->gadget);
+	if (retval) {
+		dum->driver = NULL;
+		dum->gadget.dev.driver = NULL;
+		return retval;
+	}
 
 	/* khubd will enumerate this in a while */
 	spin_lock_irq (&dum->lock);
@@ -793,20 +792,6 @@ usb_gadget_register_driver (struct usb_gadget_driver *driver)
 
 	usb_hcd_poll_rh_status (dummy_to_hcd (dum));
 	return 0;
-
-err_bind_driver:
-	driver_unregister (&driver->driver);
-err_register:
-	if (driver->unbind)
-		driver->unbind (&dum->gadget);
-	spin_lock_irq (&dum->lock);
-	dum->pullup = 0;
-	set_link_state (dum);
-	spin_unlock_irq (&dum->lock);
-err_bind_gadget:
-	dum->driver = NULL;
-	dum->gadget.dev.driver = NULL;
-	return retval;
 }
 EXPORT_SYMBOL (usb_gadget_register_driver);
 
@@ -830,11 +815,9 @@ usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
 	spin_unlock_irqrestore (&dum->lock, flags);
 
 	driver->unbind (&dum->gadget);
+	dum->gadget.dev.driver = NULL;
 	dum->driver = NULL;
 
-	device_release_driver (&dum->gadget.dev);
-	driver_unregister (&driver->driver);
-
 	spin_lock_irqsave (&dum->lock, flags);
 	dum->pullup = 0;
 	set_link_state (dum);