--- u-boot-tools-2016.01/tools/env/fw_env.c.orig	2016-01-12 15:06:54.000000000 +0100
+++ u-boot-tools-2016.01/tools/env/fw_env.c	2016-03-22 09:47:07.014381827 +0100
@@ -1453,6 +1453,7 @@
 	int rc;
 	char dump[128];
 	char *devname;
+	int fd_test;
 
 	fp = fopen (fname, "r");
 	if (fp == NULL)
@@ -1473,6 +1474,12 @@
 		if (rc < 3)
 			continue;
 
+		fd_test = open (devname, O_RDWR);
+		if (fd_test < 0)
+			continue;
+		if (close (fd_test))
+			continue;
+
 		DEVNAME(i) = devname;
 
 		if (rc < 4)