Hi Pawel, On Friday 06 June 2014 14:31:15 Pawel Osciak wrote: > Hi Laurent, > Thanks for the patch. Did you test this to work in fileio mode? Looks > like it should, but would like to make sure. No, I haven't tested it. The OMAP4 ISS driver, which is my test target for this patch, doesn't support fileio mode. Adding VB2_READ would be easy, but the driver requires configuring the format on the file handle used for streaming, so I can't just run cat /dev/video*. > On Thu, Jun 5, 2014 at 9:23 PM, Laurent Pinchart wrote: > > When a fatal error occurs that render the device unusable, the only > > options for a driver to signal the error condition to userspace is to > > set the V4L2_BUF_FLAG_ERROR flag when dequeuing buffers and to return an > > error from the buffer prepare handler when queuing buffers. > > > > The buffer error flag indicates a transient error and can't be used by > > applications to detect fatal errors. Returning an error from vb2_qbuf() > > is thus the only real indication that a fatal error occurred. However, > > this is difficult to handle for multithreaded applications that requeue > > buffers from a thread other than the control thread. In particular the > > poll() call in the control thread will not notify userspace of the > > error. > > > > This patch adds an explicit mechanism to report fatal errors to > > userspace. Applications can call the vb2_queue_error() function to > > signal a fatal error. From this moment on, buffer preparation will > > return -EIO to userspace, and vb2_poll() will set the POLLERR flag and > > return immediately. The error flag is cleared when cancelling the queue, > > either at stream off time (through vb2_streamoff) or when releasing the > > queue with vb2_queue_release(). > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
