--- a/master/master.c	Thu Sep 28 08:29:59 2006 +0000
+++ b/master/master.c	Thu Sep 28 12:58:06 2006 +0000
@@ -109,6 +109,7 @@
 
     master->index = index;
     master->device = NULL;
+    init_MUTEX(&master->device_sem);
     atomic_set(&master->available, 1);
     INIT_LIST_HEAD(&master->slaves);
     INIT_LIST_HEAD(&master->datagram_queue);