PipelineHandlerIPU3 returns -ENOBUFS and -ENOMEM on queueing a request when there are not sufficient buffers for the request. Since the request will be successful if it is queued later when enough buffers are available. The requests failed due to a buffer shortage should be stored and retried later in the FIFO order. This introduces the queue in IPU3CameraData to do that. Signed-off-by: Hirokazu Honda <hiroh@chromium.org> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>