From 1612f20ea025f55741b2d6e8b9c91047a7324a76 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Thu, 24 Jul 2014 09:19:37 -0300 Subject: [PATCH] [media] vb2: fix vb2_poll for output streams 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 Acked-by: Marek Szyprowski Signed-off-by: Mauro Carvalho Chehab --- 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 f33508f854a4..c359006074a8 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);