1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/mtd/tests/mtd_subpagetest.c b/drivers/mtd/tests/mtd_subpagetest.c
index 2b51842d08fa..1a05bfac4eee 100644
--- a/drivers/mtd/tests/mtd_subpagetest.c
+++ b/drivers/mtd/tests/mtd_subpagetest.c
@@ -29,7 +29,7 @@
 
 #define PRINT_PREF KERN_INFO "mtd_subpagetest: "
 
-static int dev;
+static int dev = -EINVAL;
 module_param(dev, int, S_IRUGO);
 MODULE_PARM_DESC(dev, "MTD device number to use");
 
@@ -379,6 +379,13 @@ static int __init mtd_subpagetest_init(void)
 
         printk(KERN_INFO "\n");
         printk(KERN_INFO "=================================================\n");
+
+        if (dev < 0) {
+                printk(PRINT_PREF "Please specify a valid mtd-device via module paramter\n");
+                printk(KERN_CRIT "CAREFUL: This test wipes all data on the specified MTD device!\n");
+                return -EINVAL;
+        }
+
         printk(PRINT_PREF "MTD device: %d\n", dev);
 
         mtd = get_mtd_device(NULL, dev);