* Something got disconnected. Get rid of it and all of its children.
*
* If *pdev is a normal device then the parent hub must already be locked.
- * If *pdev is a root hub then this routine will acquire the
- * usb_bus_list_lock on behalf of the caller.
+ * If *pdev is a root hub then the caller must hold the usb_bus_list_lock,
+ * which protects the set of root hubs as well as the list of buses.
*
* Only hub drivers (including virtual root hub drivers for host
* controllers) should ever call this.