Hi Hirofumi, On Tuesday 25 September 2007, Hirofumi Momose wrote: > Hello, > I am totally newbie to this ML. > > Now I am trying to build livecam on ARM platform. > xawtv works well with camera (0c45:62c0=Sonix USB 2.0 Camera) but, > webcam(this is livecam program in xawtv. not camera device. pretty > confusing..) did not work. > > Precisely, webcam could capture first image (very noisy), but > failed in the second capture. It failed at ioctl(VIDIOC_REQBUFS). > > UVC driver stack is > > uvc_free_buffers() > queue->buffer[i].vma_use_count = 1 (shoud be 0) > uvc_alloc_buffers() > uvc_v4l2_do_ioctl() > > I have no idea abount this issue. > Does anyone have solutions ?
vma_use_count != 0 means the buffers are still mapped. Your report is a bit unclear. What do you mean by second capture ? Did you restart the application, or does it have a capture loop inside ? If the application doesn't exit between captures, make sure it properly unmaps the buffers with munmap() before you call VIDIOC_REQBUFS. If the application exits between captures, make it has really finished before you try to restart it. Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
