diff -r 16fddae16c94 -r ffa13db95e10 master/master.c
--- a/master/master.c	Tue Oct 24 12:06:59 2006 +0000
+++ b/master/master.c	Tue Oct 24 15:14:25 2006 +0000
@@ -58,6 +58,7 @@
 void ec_master_sync_io(ec_master_t *);
 void ec_master_idle_run(void *);
 void ec_master_eoe_run(unsigned long);
+void ec_master_check_sdo(unsigned long);
 ssize_t ec_show_master_attribute(struct kobject *, struct attribute *, char *);
 ssize_t ec_store_master_attribute(struct kobject *, struct attribute *,
                                   const char *, size_t);
@@ -130,8 +131,11 @@
     master->idle_cycle_time_pos = 0;
     master->eoe_cycle_time_pos = 0;
     master->debug_level = 0;
-    INIT_LIST_HEAD(&master->sdo_requests);
-    init_waitqueue_head(&master->sdo_wait_queue);
+    init_MUTEX(&master->sdo_sem);
+    init_timer(&master->sdo_timer);
+    master->sdo_timer.function = ec_master_check_sdo;
+    master->sdo_timer.data = (unsigned long) master;
+    init_completion(&master->sdo_complete);
 
     // create workqueue
     if (!(master->workqueue = create_singlethread_workqueue("EtherCAT"))) {
@@ -301,14 +305,11 @@
 
 void ec_master_flush_sdo_requests(ec_master_t *master)
 {
-    ec_sdo_request_t *req, *next_req;
-
-    list_for_each_entry_safe(req, next_req, &master->sdo_requests, queue) {
-        list_del_init(&req->queue);
-        req->return_code = -1;
-    }
-
-    wake_up_interruptible(&master->sdo_wait_queue);
+    del_timer_sync(&master->sdo_timer);
+    complete(&master->sdo_complete);
+    master->sdo_request = NULL;
+    master->sdo_seq_user = 0;
+    master->sdo_seq_master = 0;
 }
 
 /*****************************************************************************/
@@ -1004,6 +1005,7 @@
 }
 
 /*****************************************************************************/
+
 /**
    Does the Ethernet-over-EtherCAT processing.
 */
@@ -1067,6 +1069,25 @@
 /*****************************************************************************/
 
 /**
+*/
+
+void ec_master_check_sdo(unsigned long data /**< master pointer */)
+{
+    ec_master_t *master = (ec_master_t *) data;
+
+    if (master->sdo_seq_master != master->sdo_seq_user) {
+        master->sdo_timer.expires = jiffies + 10;
+        add_timer(&master->sdo_timer);
+        return;
+    }
+
+    // master has processed the request
+    complete(&master->sdo_complete);
+}
+
+/*****************************************************************************/
+
+/**
    Calculates Advanced Position Adresses.
 */