[U-Boot] [PATCH] cmd: usb: check if_type before using this device

[Peng Fan]

For legacy usb storage driver, USB_MAX_STOR_DEV is defined as 7.
If we only have one usb disk on board, `usb dev 0` is ok.
But if `usb dev 1`, still ok, then `usb read xxx` will trigger
system fault and reboot.

So check if_type before using this device.

Signed-off-by: Peng Fan <peng.fan at nxp.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Hans de Goede <hdegoede at redhat.com>
Cc: Bin Meng <bmeng.cn at gmail.com>
Cc: Marek Vasut <marex at denx.de>
Cc: Stefan Roese <sr at denx.de>
Cc: Marcel Ziswiler <marcel.ziswiler at toradex.com>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Stephen Warren <swarren at nvidia.com>
---
 cmd/usb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cmd/usb.c b/cmd/usb.c
index b83d323..58d9db2 100644
--- a/cmd/usb.c
+++ b/cmd/usb.c
@@ -800,7 +800,8 @@ static int do_usb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 			int dev = (int)simple_strtoul(argv[2], NULL, 10);
 			printf("\nUSB device %d: ", dev);
 			stor_dev = blk_get_devnum_by_type(IF_TYPE_USB, dev);
-			if (stor_dev == NULL) {
+			if ((stor_dev == NULL) ||
+			    (stor_dev->if_type == IF_TYPE_UNKNOWN)) {
 				printf("unknown device\n");
 				return 1;
 			}
-- 
2.6.2