+ diff -u xenomai/ksrc/drivers/can/rtcan_dev.c.TXSEM xenomai/ksrc/drivers/can/rtcan_dev.c
--- xenomai/ksrc/drivers/can/rtcan_dev.c.TXSEM	2007-02-15 11:21:43.000000000 +0100
+++ xenomai/ksrc/drivers/can/rtcan_dev.c	2007-02-15 14:52:20.000000000 +0100
@@ -176,9 +176,9 @@
 
     rtdm_lock_init(&dev->device_lock);
 
-    /* Init TX Semaphore, will be destroyed forthwith
-     * when setting stop mode */
+    /* Init and destroy TX semaphore to mark TX unavailable. */
     rtdm_sem_init(&dev->tx_sem, 0);
+    rtdm_sem_destroy(&dev->tx_sem);
 #ifdef RTCAN_USE_REFCOUNT
     atomic_set(&dev->refcount, 0);
 #endif
+ diff -u xenomai/ksrc/drivers/can/rtcan_raw_dev.c.TXSEM xenomai/ksrc/drivers/can/rtcan_raw_dev.c
--- xenomai/ksrc/drivers/can/rtcan_raw_dev.c.TXSEM	2007-02-15 11:21:43.000000000 +0100
+++ xenomai/ksrc/drivers/can/rtcan_raw_dev.c	2007-02-15 14:16:16.000000000 +0100
@@ -193,7 +193,8 @@
     switch (request) {
     case SIOCSCANMODE:
 	mode = (can_mode_t *)&ifr->ifr_ifru;
-	if (dev->do_set_mode)
+	if (dev->do_set_mode &&
+	    !(*mode == CAN_MODE_START && CAN_STATE_OPERATING(dev->state)))
 	    ret = dev->do_set_mode(dev, *mode, &lock_ctx);
 	break;