2 Replies Latest reply on Oct 10, 2017 5:58 AM by yann.wanwanscappel_2505661

    Max burst limited to 1 when developping a USB composite device (FX3)

    yann.wanwanscappel_2505661

      Hello,

       

      I'm developping a USB composite device that provides two functionnalities:

       

      - Data streaming from USB device to USB host.  : one USB interface, one bulk endpoint

      - A virtual COM port for controling the device : CDC class device,

       

      When I put only the streaming interface in the superspeed configuration device, all is OK.  The burst size set in the endpoint companion is properly set and I am able to handle the throughput of the video stream sent by the device.

       

      When I put both configurations in the superspeed configuration device, after customization of .inf files,  both devices are seen on windows (streaming device + serial port), but I am no longer able to handle the video stream.

       

      Printing the video stream endpoint ssmaxburst parameter shows that the ssmaxburst is no longer set to 15 but to 0, as if the superspeed endpoint companion has been ignored in this case (note that I am working on Win7).

       

      Dumping the usb descriptors in linux (lsusb -v) shows that in both cases, the max burst size is set to 15.

       

      Did someone already faced that issue ? How to fix it ?

       

      I attached the usb descriptors for reference.

       

      Regards,

      Yann