diff -r bd150d066ea2 -r 4844a8433915 master/cdev.c
--- a/master/cdev.c	Fri Aug 21 09:45:53 2009 +0200
+++ b/master/cdev.c	Fri Aug 21 09:46:29 2009 +0200
@@ -175,6 +175,7 @@
     data.eoe_handler_count = ec_master_eoe_handler_count(master);
 #endif
     data.phase = (uint8_t) master->phase;
+    data.active = (uint8_t) master->active;
     data.scan_busy = master->scan_busy;
     up(&master->master_sem);
 
@@ -1647,6 +1648,23 @@
 
 /*****************************************************************************/
 
+/** Deactivates the master.
+ */
+int ec_cdev_ioctl_deactivate(
+        ec_master_t *master, /**< EtherCAT master. */
+        unsigned long arg, /**< ioctl() argument. */
+        ec_cdev_priv_t *priv /**< Private data structure of file handle. */
+        )
+{
+    if (unlikely(!priv->requested))
+        return -EPERM;
+
+    ecrt_master_deactivate(master);
+    return 0;
+}
+
+/*****************************************************************************/
+
 /** Send frames.
  */
 int ec_cdev_ioctl_send(
@@ -3262,6 +3280,10 @@
             if (!(filp->f_mode & FMODE_WRITE))
                 return -EPERM;
             return ec_cdev_ioctl_activate(master, arg, priv);
+        case EC_IOCTL_DEACTIVATE:
+            if (!(filp->f_mode & FMODE_WRITE))
+                return -EPERM;
+            return ec_cdev_ioctl_deactivate(master, arg, priv);
         case EC_IOCTL_SEND:
             if (!(filp->f_mode & FMODE_WRITE))
                 return -EPERM;