usb: gadget: uvc: Only halt video streaming endpoint in bulk mode

When USB requests for video data fail to be submitted, the driver
signals a problem to the host by halting the video streaming endpoint.
This is only valid in bulk mode, as isochronous transfers have no
handshake phase and can't thus report a stall. The usb_ep_set_halt()
call returns an error when using isochronous endpoints, which we happily
ignore, but some UDCs complain in the kernel log. Fix this by only
trying to halt the endpoint in bulk mode.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index a95c8e2364edcc1dbf6d66fcfc6a75fa25b0ba05..2c9821ec836e771e3c22b0899da60974ff2417fb 100644 (file)
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -132,7 +132,9 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
        ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
        if (ret < 0) {
                printk(KERN_INFO "Failed to queue request (%d).\n", ret);
-               usb_ep_set_halt(video->ep);
+               /* Isochronous endpoints can't be halted. */
+               if (usb_endpoint_xfer_bulk(video->ep->desc))
+                       usb_ep_set_halt(video->ep);
        }
 
        return ret;