diff -r 505cf41488a4 -r 9cdd7669dc0b master/ioctl.c
--- a/master/ioctl.c	Thu Jan 10 12:34:58 2013 +0100
+++ b/master/ioctl.c	Thu Jan 10 17:36:41 2013 +0100
@@ -1753,12 +1753,11 @@
         ec_ioctl_context_t *ctx /**< Private data structure of file handle. */
         )
 {
-    if (unlikely(!ctx->requested))
-        return -EPERM;
-
-    down(&master->io_sem);
+    if (unlikely(!ctx->requested)) {
+        return -EPERM;
+    }
+
     ecrt_master_send(master);
-    up(&master->io_sem);
     return 0;
 }
 
@@ -1772,12 +1771,11 @@
         ec_ioctl_context_t *ctx /**< Private data structure of file handle. */
         )
 {
-    if (unlikely(!ctx->requested))
-        return -EPERM;
-
-    down(&master->io_sem);
+    if (unlikely(!ctx->requested)) {
+        return -EPERM;
+    }
+
     ecrt_master_receive(master);
-    up(&master->io_sem);
     return 0;
 }
 
@@ -1864,12 +1862,11 @@
         ec_ioctl_context_t *ctx /**< Private data structure of file handle. */
         )
 {
-    if (unlikely(!ctx->requested))
-        return -EPERM;
-
-    down(&master->io_sem);
+    if (unlikely(!ctx->requested)) {
+        return -EPERM;
+    }
+
     ecrt_master_sync_reference_clock(master);
-    up(&master->io_sem);
     return 0;
 }
 
@@ -1883,12 +1880,11 @@
         ec_ioctl_context_t *ctx /**< Private data structure of file handle. */
         )
 {
-    if (unlikely(!ctx->requested))
-        return -EPERM;
-
-    down(&master->io_sem);
+    if (unlikely(!ctx->requested)) {
+        return -EPERM;
+    }
+
     ecrt_master_sync_slave_clocks(master);
-    up(&master->io_sem);
     return 0;
 }
 
@@ -1931,12 +1927,11 @@
         ec_ioctl_context_t *ctx /**< Private data structure of file handle. */
         )
 {
-    if (unlikely(!ctx->requested))
-        return -EPERM;
-
-    down(&master->io_sem);
+    if (unlikely(!ctx->requested)) {
+        return -EPERM;
+    }
+
     ecrt_master_sync_monitor_queue(master);
-    up(&master->io_sem);
     return 0;
 }