ioctl(hCapture->fd, VIDIOC_DQBUF, &v4l2buf) Locked!

Hi 

   When I run "./video_loopback_copy_omapl138.x470MV -r720x576", it will locked at:

./video_loopback_copy_omapl138.x470MV -r720x576

   In file:

dvsdk_04_03/dmai_2_20_00_15/packages/ti/sdo/dmai/linux/omapl138/Capture.c

  v4l2buf.memory = V4L2_MEMORY_MMAP

What's problem? Who can help me to do that?

Thanks very much!