diff mbox

v4l: videobuf: make poll() report proper flags for output video devices

Message ID 1268834402-31355-1-git-send-email-p.osciak@samsung.com (mailing list archive)
State Superseded, archived
Headers

Commit Message

Pawel Osciak March 17, 2010, 2 p.m. UTC 
  According to the V4L2 specification, poll() should set POLLOUT | POLLWRNORM
flags for output devices after the frame has been displayed.

Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/media/video/videobuf-core.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

Comments

Hans Verkuil March 17, 2010, 8:14 p.m. UTC | #1 
On Wednesday 17 March 2010 15:00:02 Pawel Osciak wrote:
> According to the V4L2 specification, poll() should set POLLOUT | POLLWRNORM
> flags for output devices after the frame has been displayed.
> 
> Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
> Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  drivers/media/video/videobuf-core.c |   10 ++++++++--
>  1 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
> index 37afb4e..e93672a 100644
> --- a/drivers/media/video/videobuf-core.c
> +++ b/drivers/media/video/videobuf-core.c
> @@ -1075,8 +1075,14 @@ unsigned int videobuf_poll_stream(struct file *file,
>  	if (0 == rc) {
>  		poll_wait(file, &buf->done, wait);
>  		if (buf->state == VIDEOBUF_DONE ||
> -		    buf->state == VIDEOBUF_ERROR)
> -			rc = POLLIN|POLLRDNORM;
> +		    buf->state == VIDEOBUF_ERROR) {
> +			if (q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +				rc = POLLIN | POLLRDNORM;
> +			else if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
> +				rc = POLLOUT | POLLWRNORM;
> +			else
> +				BUG();
> +		}

This is not right. First of all you shouldn't call BUG here. It is better to
default to POLLIN|POLLRDNORM. Secondly, there are more types than just these
two.

This is better:

	switch (q->type) {
		case V4L2_BUF_TYPE_VIDEO_OUTPUT:
		case V4L2_BUF_TYPE_VBI_OUTPUT:
		case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
			rc = POLLOUT | POLLWRNORM;
			break;
		default:
			rc = POLLIN | POLLRDNORM;
			break;
	}

Regards,

	Hans


>  	}
>  	mutex_unlock(&q->vb_lock);
>  	return rc;
>
diff mbox

Patch

diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index 37afb4e..e93672a 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -1075,8 +1075,14 @@  unsigned int videobuf_poll_stream(struct file *file,
 	if (0 == rc) {
 		poll_wait(file, &buf->done, wait);
 		if (buf->state == VIDEOBUF_DONE ||
-		    buf->state == VIDEOBUF_ERROR)
-			rc = POLLIN|POLLRDNORM;
+		    buf->state == VIDEOBUF_ERROR) {
+			if (q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+				rc = POLLIN | POLLRDNORM;
+			else if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
+				rc = POLLOUT | POLLWRNORM;
+			else
+				BUG();
+		}
 	}
 	mutex_unlock(&q->vb_lock);
 	return rc;