On 4/1/19 5:14 AM, Hans Verkuil wrote:
Hi Shuah,
On 3/30/19 2:54 AM, Shuah Khan wrote:
Enable and disable source interfaces aren't consistent in enforcing
how video and audio share the tuner resource.
Fix these issues to enforce the following rules and allow
sharing between audio and video applications.
- When DVB is streaming, audio/video/vbi/s-video/composite
should find the resource busy. DVB holds the tuner in
exclusive mode.
- When video is streaming, audio can share the tuner and vice versa.
- v4l2 allows multiple applications to open video device.
- Video applications call enable source multiple times during their
run-time. Resource should stay locked until the last application
releases it.
- A shared resource should stay in shared state and locked when it is
in use by audio and video. More than one video application is allowed
to use the tuner as long as video streaming protocol allows such usage.
Resource is released when the last video/audio application releases it.
- S-Video and Composite hold the resource in exclusive mode.
- VBI allows more than vbi applications sharing and will not share
with another type. When resource is locked by VBI and in use by
multiple VBI applications, it should stay locked until the last
application disables it.
This isn't correct: only one application at most can stream VBI, but
VBI can be shared with video and audio streaming.
All three come from the same source (analog TV), so as long as one of
these is streaming the analog tuner resource is in use.
With this patch it seems that streaming VBI blocks streaming audio/video
and vice versa. That's wrong.
Right. The reason I went this route is that VBI streaming stops even
when another VBI starts to stream. I am debugging this. Looks like
you have a fix for this from reading below.
Otherwise everything looks OK, except for a typo below.
Will fix the typos and also I noticed, I forgot to catch updating
Copyright in one of the files.
Signed-off-by: Shuah Khan <shuah@xxxxxxxxxx>
---
drivers/media/usb/au0828/au0828-core.c | 182 +++++++++++++++++++------
drivers/media/usb/au0828/au0828.h | 5 +-
2 files changed, 148 insertions(+), 39 deletions(-)
diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index 4f8ba6f64d3c..b8bcab2fa1dc 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -272,6 +272,27 @@ static void au0828_media_graph_notify(struct media_entity *new,
}
}
+static bool au0828_is_link_sharable(struct media_entity *owner,
+ struct media_entity *entity)
+{
+ bool sharable = false;
typo: sharable -> shareable
Also in the function name: do a search-and-replace for this.
Will do.
+
+ /* Tuner link can be shared by audio and video */
add: and VBI
I think the core issue is here since VBI should be included with
IO_V4L and AUDIO_CAPTURE.
+ switch (owner->function) {
+ case MEDIA_ENT_F_IO_V4L:
+ case MEDIA_ENT_F_AUDIO_CAPTURE:
+ if (entity->function == MEDIA_ENT_F_IO_V4L ||
+ entity->function == MEDIA_ENT_F_AUDIO_CAPTURE)
+ sharable = true;
+ break;
+ case MEDIA_ENT_F_DTV_DEMOD:
+ case MEDIA_ENT_F_IO_VBI:
+ default:
+ break;
+ }
+ return sharable;
I hacked this function so VBI is included with IO_V4L/AUDIO_CAPTURE
and now it works.
Yes. Y have been debugging with VBI included in the sharing, however
running into the below problem. Do you have the patch I can use to
test with this series?
There is one remaining issue (but that was always a problem with au0828):
when streaming is in progress from both video and vbi, and then you stop
the video streaming, then vbi stops as well.
au0828_stop_streaming() calls v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_stream, 0);
which it should only do when the last user disappears. I'll post a patch
for au0828 to fix this.
Thanks for finding this problem. I narrowed it to close and didn't get
a chance to play with it.
thanks,
-- Shuah
