vb2_poll should always return POLLOUT | POLLWRNORM as long as there are fewer buffers queued than there are buffers available. Poll for an output stream should only wait if all buffers are queued and nobody is dequeuing them. Signed-off-by: Hans Verkuil <hansverk@xxxxxxxxx> --- drivers/media/v4l2-core/videobuf2-core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index f33508f..c359006 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2596,6 +2596,13 @@ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) if ((list_empty(&q->queued_list) && !vb2_is_streaming(q)) || q->error) return res | POLLERR; + /* + * For output streams you can write as long as there are fewer buffers + * queued than there are buffers available. + */ + if (V4L2_TYPE_IS_OUTPUT(q->type) && q->queued_count < q->num_buffers) + return res | POLLOUT | POLLWRNORM; + if (list_empty(&q->done_list)) poll_wait(file, &q->done_wq, wait); -- 2.0.0.rc0 -- 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
