diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 1d3be80..a09deea 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -108,6 +108,24 @@
 
 extern int css_get_ssd_info(struct subchannel *sch);
 
+
+int css_sch_device_register(struct subchannel *sch)
+{
+	int ret;
+
+	mutex_lock(&sch->reg_mutex);
+	ret = device_register(&sch->dev);
+	mutex_unlock(&sch->reg_mutex);
+	return ret;
+}
+
+void css_sch_device_unregister(struct subchannel *sch)
+{
+	mutex_lock(&sch->reg_mutex);
+	device_unregister(&sch->dev);
+	mutex_unlock(&sch->reg_mutex);
+}
+
 static int
 css_register_subchannel(struct subchannel *sch)
 {
@@ -119,7 +137,7 @@
 	sch->dev.release = &css_subchannel_release;
 	
 	/* make it known to the system */
-	ret = device_register(&sch->dev);
+	ret = css_sch_device_register(sch);
 	if (ret)
 		printk (KERN_WARNING "%s: could not register %s\n",
 			__func__, sch->dev.bus_id);
@@ -250,7 +268,7 @@
 		 * The device will be killed automatically.
 		 */
 		cio_disable_subchannel(sch);
-		device_unregister(&sch->dev);
+		css_sch_device_unregister(sch);
 		/* Reset intparm to zeroes. */
 		sch->schib.pmcw.intparm = 0;
 		cio_modify(sch);
@@ -264,7 +282,7 @@
 		 * away in any case.
 		 */
 		if (!disc) {
-			device_unregister(&sch->dev);
+			css_sch_device_unregister(sch);
 			/* Reset intparm to zeroes. */
 			sch->schib.pmcw.intparm = 0;
 			cio_modify(sch);