Index: usb-devel/drivers/usb/class/usbtmc.c
===================================================================
--- usb-devel.orig/drivers/usb/class/usbtmc.c
+++ usb-devel/drivers/usb/class/usbtmc.c
@@ -1928,6 +1928,8 @@ static int usbtmc_ioctl_request(struct u
 
 	if (request.req.wLength > USBTMC_BUFSIZE)
 		return -EMSGSIZE;
+	if (request.req.wLength == 0)	/* Length-0 requests are never IN */
+		request.req.bRequestType &= ~USB_DIR_IN;
 
 	is_in = request.req.bRequestType & USB_DIR_IN;