Index: uspace/lib/usbdev/include/usb/dev/poll.h
===================================================================
--- uspace/lib/usbdev/include/usb/dev/poll.h	(revision 6e3c00597c8370c902914c8528e2d7eebd7aa5c6)
+++ uspace/lib/usbdev/include/usb/dev/poll.h	(revision 64846020196dc6d7df55370e22747216c5237afc)
@@ -83,8 +83,10 @@
 	 */
 	bool (*on_error)(usb_device_t *dev, int err_code, void *arg);
+	/** Argument to pass to callbacks. */
+	void *arg;
 } usb_device_auto_polling_t;
 
 int usb_device_auto_polling(usb_device_t *, size_t,
-    const usb_device_auto_polling_t *, size_t, void *);
+    const usb_device_auto_polling_t *, size_t);
 
 typedef bool (*usb_polling_callback_t)(usb_device_t *,