diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index e9bfcfd..c3c9804 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -408,7 +408,7 @@
 	if (!cs)
 		return;
 
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	if (!cs->bcs)
 		goto f_cs;
@@ -459,7 +459,7 @@
 f_bcs:	gig_dbg(DEBUG_INIT, "freeing bcs[]");
 	kfree(cs->bcs);
 f_cs:	gig_dbg(DEBUG_INIT, "freeing cs");
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 	free_cs(cs);
 }
 EXPORT_SYMBOL_GPL(gigaset_freecs);
@@ -652,7 +652,9 @@
 	spin_lock_init(&cs->ev_lock);
 	atomic_set(&cs->ev_tail, 0);
 	atomic_set(&cs->ev_head, 0);
-	init_MUTEX_LOCKED(&cs->sem);
+	mutex_init(&cs->mutex);
+	mutex_lock(&cs->mutex);
+
 	tasklet_init(&cs->event_tasklet, &gigaset_handle_event,
 		     (unsigned long) cs);
 	atomic_set(&cs->commands_pending, 0);
@@ -729,11 +731,11 @@
 	add_timer(&cs->timer);
 
 	gig_dbg(DEBUG_INIT, "cs initialized");
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 	return cs;
 
 error:	if (cs)
-		up(&cs->sem);
+		mutex_unlock(&cs->mutex);
 	gig_dbg(DEBUG_INIT, "failed");
 	gigaset_freecs(cs);
 	return NULL;
@@ -831,7 +833,7 @@
 
 int gigaset_start(struct cardstate *cs)
 {
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return 0;
 
 	atomic_set(&cs->connected, 1);
@@ -861,18 +863,18 @@
 	/* set up device sysfs */
 	gigaset_init_dev_sysfs(cs);
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 	return 1;
 
 error:
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(gigaset_start);
 
 void gigaset_shutdown(struct cardstate *cs)
 {
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	cs->waiting = 1;
 
@@ -902,13 +904,13 @@
 	cleanup_cs(cs);
 
 exit:
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 }
 EXPORT_SYMBOL_GPL(gigaset_shutdown);
 
 void gigaset_stop(struct cardstate *cs)
 {
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	/* clear device sysfs */
 	gigaset_free_dev_sysfs(cs);
@@ -936,7 +938,7 @@
 	cleanup_cs(cs);
 
 exit:
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 }
 EXPORT_SYMBOL_GPL(gigaset_stop);
 
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index 7a44cac..12153ac 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -497,7 +497,7 @@
 	int cs_init;
 	int ignoreframes;		/* frames to ignore after setting up the
 					   B channel */
-	struct semaphore sem;		/* locks this structure:
+	struct mutex mutex;		/* locks this structure:
 					 *   connected is not changed,
 					 *   hardware_up is not changed,
 					 *   MState is not changed to or from
diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c
index 2575086..ac408ac 100644
--- a/drivers/isdn/gigaset/interface.c
+++ b/drivers/isdn/gigaset/interface.c
@@ -160,7 +160,7 @@
 	if (!cs)
 		return -ENODEV;
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 	tty->driver_data = cs;
 
@@ -173,7 +173,7 @@
 		tty->low_latency = 1; //FIXME test
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 	return 0;
 }
 
@@ -190,7 +190,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	if (!cs->open_count)
 		warn("%s: device not opened", __func__);
@@ -202,7 +202,7 @@
 		}
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 }
 
 static int if_ioctl(struct tty_struct *tty, struct file *file,
@@ -222,7 +222,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	if (!cs->open_count)
@@ -279,7 +279,7 @@
 		}
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return retval;
 }
@@ -297,13 +297,13 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	// FIXME read from device?
 	retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return retval;
 }
@@ -324,7 +324,7 @@
 	gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 		cs->minor_index, __func__, set, clear);
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	if (!atomic_read(&cs->connected)) {
@@ -336,7 +336,7 @@
 		cs->control_state = mc;
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return retval;
 }
@@ -354,7 +354,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	if (!cs->open_count)
@@ -370,7 +370,7 @@
 					    &cs->if_wake_tasklet);
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return retval;
 }
@@ -388,7 +388,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	if (!cs->open_count)
@@ -402,7 +402,7 @@
 	} else
 		retval = cs->ops->write_room(cs);
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return retval;
 }
@@ -420,7 +420,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	if (!cs->open_count)
@@ -434,7 +434,7 @@
 	} else
 		retval = cs->ops->chars_in_buffer(cs);
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return retval;
 }
@@ -451,7 +451,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	if (!cs->open_count)
 		warn("%s: device not opened", __func__);
@@ -459,7 +459,7 @@
 		//FIXME
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 }
 
 static void if_unthrottle(struct tty_struct *tty)
@@ -474,7 +474,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	if (!cs->open_count)
 		warn("%s: device not opened", __func__);
@@ -482,7 +482,7 @@
 		//FIXME
 	}
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 }
 
 static void if_set_termios(struct tty_struct *tty, struct termios *old)
@@ -501,7 +501,7 @@
 
 	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 
-	down(&cs->sem);
+	mutex_lock(&cs->mutex);
 
 	if (!cs->open_count) {
 		warn("%s: device not opened", __func__);
@@ -586,7 +586,7 @@
 	cs->control_state = control_state;
 
 out:
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 }
 
 
diff --git a/drivers/isdn/gigaset/proc.c b/drivers/isdn/gigaset/proc.c
index 912fed6..8f124e8 100644
--- a/drivers/isdn/gigaset/proc.c
+++ b/drivers/isdn/gigaset/proc.c
@@ -37,14 +37,14 @@
 	if (value < 0 || value > 1)
 			return -EINVAL;
 
-	if (down_interruptible(&cs->sem))
+	if (mutex_lock_interruptible(&cs->mutex))
 		return -ERESTARTSYS; // FIXME -EINTR?
 
 	cs->waiting = 1;
 	if (!gigaset_add_event(cs, &cs->at_state, EV_PROC_CIDMODE,
 			       NULL, value, NULL)) {
 		cs->waiting = 0;
-		up(&cs->sem);
+		mutex_unlock(&cs->mutex);
 		return -ENOMEM;
 	}
 
@@ -53,7 +53,7 @@
 
 	wait_event(cs->waitqueue, !cs->waiting);
 
-	up(&cs->sem);
+	mutex_unlock(&cs->mutex);
 
 	return count;
 }