[v2,08/14,media] v4l: add support to BUF_QUEUED event

Message ID 20170901015041.7757-9-gustavo@padovan.org (mailing list archive)
State Superseded, archived
Delegated to: Hans Verkuil
Headers

Commit Message

Gustavo F. Padovan Sept. 1, 2017, 1:50 a.m. UTC
  From: Gustavo Padovan <gustavo.padovan@collabora.com>

Implement the needed pieces to let userspace subscribe for
V4L2_EVENT_BUF_QUEUED events. Videobuf2 will queue the event for the
DQEVENT ioctl.

v3:	- Do not call v4l2 event API from vb2 (Mauro)

v2:	- Use VIDEO_MAX_FRAME to allocate room for events at
	v4l2_event_subscribe() (Hans)

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c     |  6 +++++-
 drivers/media/v4l2-core/videobuf2-core.c |  2 ++
 drivers/media/v4l2-core/videobuf2-v4l2.c | 13 +++++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)
  

Comments

Sakari Ailus Oct. 15, 2017, 9:25 p.m. UTC | #1
Hi Gustavo,

On Thu, Aug 31, 2017 at 10:50:35PM -0300, Gustavo Padovan wrote:
> From: Gustavo Padovan <gustavo.padovan@collabora.com>
> 
> Implement the needed pieces to let userspace subscribe for
> V4L2_EVENT_BUF_QUEUED events. Videobuf2 will queue the event for the
> DQEVENT ioctl.
> 
> v3:	- Do not call v4l2 event API from vb2 (Mauro)
> 
> v2:	- Use VIDEO_MAX_FRAME to allocate room for events at
> 	v4l2_event_subscribe() (Hans)
> 
> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
> ---
>  drivers/media/v4l2-core/v4l2-ctrls.c     |  6 +++++-
>  drivers/media/v4l2-core/videobuf2-core.c |  2 ++
>  drivers/media/v4l2-core/videobuf2-v4l2.c | 13 +++++++++++++
>  3 files changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index dd1db678718c..17d4b9e3eec6 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -3438,8 +3438,12 @@ EXPORT_SYMBOL(v4l2_ctrl_log_status);
>  int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
>  				const struct v4l2_event_subscription *sub)
>  {
> -	if (sub->type == V4L2_EVENT_CTRL)
> +	switch (sub->type) {
> +	case V4L2_EVENT_CTRL:
>  		return v4l2_event_subscribe(fh, sub, 0, &v4l2_ctrl_sub_ev_ops);
> +	case V4L2_EVENT_BUF_QUEUED:
> +		return v4l2_event_subscribe(fh, sub, VIDEO_MAX_FRAME, NULL);

While I think this is probably the correct place to add the event
subscription handling, the name of the function no longer corresponds what
it does, nor it belongs to v4l2-ctrls.c.

v4l2_ctrl_subscribe_event() is also used for subscribing control events on
sub-devices. BUF_QUEUED events will be available only on video nodes.

BUF_QUEUED events presumably should be availble on all video nodes that
support V4L2_CAP_STREAMING capability. Perhaps this could be handled by
moving v4l2_ctrl_subscribe_event() to v4l2-event.c and renaming it e.g.
v4l2_event_subscribe_v4l2(), for these events originate from specific
conditions the V4L2 framework is aware of.
v4l2_ctrl_subdev_subscribe_event() handling needs to be addressed as well.

A separate patch would be nice. 

> +	}
>  	return -EINVAL;
>  }
>  EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
> index b19c1bc4b083..bbbae0eed567 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -1231,6 +1231,8 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
>  	trace_vb2_buf_queue(q, vb);
>  
>  	call_void_vb_qop(vb, buf_queue, vb);
> +
> +	call_void_bufop(q, buffer_queued, vb);
>  }
>  
>  static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
> diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
> index 8c322cd1b346..1c93bfedaffc 100644
> --- a/drivers/media/v4l2-core/videobuf2-v4l2.c
> +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
> @@ -138,6 +138,18 @@ static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
>  	}
>  };
>  
> +static void __buffer_queued(struct vb2_buffer *vb)
> +{
> +	struct video_device *vdev = to_video_device(vb->vb2_queue->dev);
> +	struct v4l2_event event;
> +
> +	memset(&event, 0, sizeof(event));
> +	event.type = V4L2_EVENT_BUF_QUEUED;
> +	event.u.buf_queued.index = vb->index;
> +
> +	v4l2_event_queue(vdev, &event);
> +}
> +
>  static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
>  {
>  	static bool check_once;
> @@ -455,6 +467,7 @@ static const struct vb2_buf_ops v4l2_buf_ops = {
>  	.fill_user_buffer	= __fill_v4l2_buffer,
>  	.fill_vb2_buffer	= __fill_vb2_buffer,
>  	.copy_timestamp		= __copy_timestamp,
> +	.buffer_queued		= __buffer_queued,
>  };
>  
>  /**
  

Patch

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index dd1db678718c..17d4b9e3eec6 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3438,8 +3438,12 @@  EXPORT_SYMBOL(v4l2_ctrl_log_status);
 int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
 				const struct v4l2_event_subscription *sub)
 {
-	if (sub->type == V4L2_EVENT_CTRL)
+	switch (sub->type) {
+	case V4L2_EVENT_CTRL:
 		return v4l2_event_subscribe(fh, sub, 0, &v4l2_ctrl_sub_ev_ops);
+	case V4L2_EVENT_BUF_QUEUED:
+		return v4l2_event_subscribe(fh, sub, VIDEO_MAX_FRAME, NULL);
+	}
 	return -EINVAL;
 }
 EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index b19c1bc4b083..bbbae0eed567 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1231,6 +1231,8 @@  static void __enqueue_in_driver(struct vb2_buffer *vb)
 	trace_vb2_buf_queue(q, vb);
 
 	call_void_vb_qop(vb, buf_queue, vb);
+
+	call_void_bufop(q, buffer_queued, vb);
 }
 
 static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 8c322cd1b346..1c93bfedaffc 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -138,6 +138,18 @@  static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
 	}
 };
 
+static void __buffer_queued(struct vb2_buffer *vb)
+{
+	struct video_device *vdev = to_video_device(vb->vb2_queue->dev);
+	struct v4l2_event event;
+
+	memset(&event, 0, sizeof(event));
+	event.type = V4L2_EVENT_BUF_QUEUED;
+	event.u.buf_queued.index = vb->index;
+
+	v4l2_event_queue(vdev, &event);
+}
+
 static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
 {
 	static bool check_once;
@@ -455,6 +467,7 @@  static const struct vb2_buf_ops v4l2_buf_ops = {
 	.fill_user_buffer	= __fill_v4l2_buffer,
 	.fill_vb2_buffer	= __fill_vb2_buffer,
 	.copy_timestamp		= __copy_timestamp,
+	.buffer_queued		= __buffer_queued,
 };
 
 /**