The "r" variable is an int and "bufsize" is an unsigned int so the comparison is type promoted to unsigned. If usb_control_msg() returns a negative that is treated as a high positive value and the error handling doesn't work. Fixes: 2d5a9c72d0c4 ("USB: serial: ch341: fix control-message error handling") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index bdd7a5ad3bf1..3bb1fff02bed 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -128,7 +128,7 @@ static int ch341_control_in(struct usb_device *dev, r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, value, index, buf, bufsize, DEFAULT_TIMEOUT); - if (r < bufsize) { + if (r < (int)bufsize) { if (r >= 0) { dev_err(&dev->dev, "short control message received (%d < %u)\n", -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html