cmd_usb.c: show cmd usage if no args given

Signed-off-by: Serge Ziryukin <ftrvxmtrx@gmail.com>

diff --git a/common/cmd_usb.c b/common/cmd_usb.c
index ee3755c121cda7336c75e1e75679afd1694886b2..fcb5f763c020d2c5b466329d4da412f3bb86c19a 100644 (file)
--- a/common/cmd_usb.c
+++ b/common/cmd_usb.c
@@ -516,6 +516,11 @@ int do_usb(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
        block_dev_desc_t *stor_dev;
 #endif
 
+       if (argc < 2) {
+               cmd_usage(cmdtp);
+               return 1;
+       }
+
        if ((strncmp(argv[1], "reset", 5) == 0) ||
                 (strncmp(argv[1], "start", 5) == 0)) {
                usb_stop();