diff --git a/include/asm-s390/cio.h b/include/asm-s390/cio.h
index cabd5bb74b5a..d92785030980 100644
--- a/include/asm-s390/cio.h
+++ b/include/asm-s390/cio.h
@@ -278,7 +278,10 @@ struct ccw_dev_id {
 static inline int ccw_dev_id_is_equal(struct ccw_dev_id *dev_id1,
 				      struct ccw_dev_id *dev_id2)
 {
-	return !memcmp(dev_id1, dev_id2, sizeof(struct ccw_dev_id));
+	if ((dev_id1->ssid == dev_id2->ssid) &&
+	    (dev_id1->devno == dev_id2->devno))
+		return 1;
+	return 0;
 }
 
 extern int diag210(struct diag210 *addr);