Index: uspace/srv/devman/main.c
===================================================================
--- uspace/srv/devman/main.c	(revision 224c0e7cdf71623ced2dfae1613f0f4c6f94d45b)
+++ uspace/srv/devman/main.c	(revision 5b68e0ca93e8b5310f537cf69218025800ed6aab)
@@ -326,4 +326,12 @@
 			}
 			
+			/* Verify that driver removed all functions */
+			fibril_rwlock_read_lock(&device_tree.rwlock);
+			if (!list_empty(&dev->functions)) {
+				fibril_rwlock_read_unlock(&device_tree.rwlock);
+				return EIO;
+			}
+			fibril_rwlock_read_unlock(&device_tree.rwlock);
+			
 			detach_driver(&device_tree, dev);