[alsa-devel] [PATCH 09/31] media: v4l2-core add v4l_vb2q_enable_media_tuner() helper
Mauro Carvalho Chehab
mchehab at osg.samsung.com
Thu Jan 28 18:34:39 CET 2016
Em Thu, 28 Jan 2016 10:31:21 -0700
Shuah Khan <shuahkh at osg.samsung.com> escreveu:
> On 01/28/2016 08:29 AM, Mauro Carvalho Chehab wrote:
> > Em Wed, 6 Jan 2016 13:26:58 -0700
> > Shuah Khan <shuahkh at osg.samsung.com> escreveu:
> >
> >> Add a new v4l_vb2q_enable_media_tuner() wrapper function
> >> to be called from v4l2-core to enable the media tuner with
> >> videobuf2 queue, when the calling frunction has the videobuf2
> >> queue and doesn't have the struct video_device associated with
> >> the queue handy as in the case of vb2_core_streamon(). This
> >> function simply calls v4l_enable_media_tuner() passing in the
> >> pointer to struct video_device.
> >>
> >> Signed-off-by: Shuah Khan <shuahkh at osg.samsung.com>
> >> ---
> >> drivers/media/v4l2-core/v4l2-dev.c | 21 +++++++++++++++++++++
> >> include/media/v4l2-dev.h | 1 +
> >> 2 files changed, 22 insertions(+)
> >>
> >> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> >> index f06da6e..9ef675a 100644
> >> --- a/drivers/media/v4l2-core/v4l2-dev.c
> >> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> >> @@ -30,6 +30,7 @@
> >> #include <media/v4l2-common.h>
> >> #include <media/v4l2-device.h>
> >> #include <media/v4l2-ioctl.h>
> >> +#include <media/videobuf2-core.h>
> >>
> >> #define VIDEO_NUM_DEVICES 256
> >> #define VIDEO_NAME "video4linux"
> >> @@ -261,6 +262,26 @@ void v4l_disable_media_tuner(struct video_device *vdev)
> >> }
> >> EXPORT_SYMBOL_GPL(v4l_disable_media_tuner);
> >>
> >> +/**
> >> + * v4l_vb2q_enable_media_tuner - Wrapper for v4l_enable_media_tuner()
> >> + * @q: videobuf2 queue
> >> + *
> >> + * This function is intended to be called from v4l2-core
> >> + * to enable the media tuner with videobuf2 queue, when
> >> + * the calling frunction has the videobuf2 queue and doesn't
> >
> > typo: function
>
> ok thanks
>
> >
> >> + * have the struct video_device associated with the
> >> + * queue handy as in the case of vb2_core_streamon(). This
> >> + * function simply calls v4l_enable_media_tuner() passing
> >> + * in the pointer to struct video_device.
> >
> > The hole description seems confusing. I'm not seeing the light
> > about why this is needed.
>
> Sorry if the description isn't clear. During videobuf2
> work, owner field in struct vb2_queue is changed from
> struct v4l2_fh * to void. Prior to this work, I could
> call v4l_enable_media_tuner().
>
> + ret = v4l_enable_media_tuner(q->owner->vdev);
> + if (ret)
> + return ret;
>
> As you can see with the videobuf2, to be able to call
> v4l_enable_media_tuner() from vb2_core_streamon(), I have
> had to this wrapper to maintain the abstraction introduced
> in videobuf2 work.
>
> Hope this helps the need for this wrapper.
It is clearer now. Please improve the description of the patch
on the next version for us to remember ;)
Regards,
Mauro
>
> thanks,
> -- Shuah
> >
> >> + */
> >> +int v4l_vb2q_enable_media_tuner(struct vb2_queue *q)
> >> +{
> >> + struct v4l2_fh *fh = q->owner;
> >> +
> >> + return v4l_enable_media_tuner(fh->vdev);
> >> +}
> >> +EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_tuner);
> >> +
> >> /* Priority handling */
> >>
> >> static inline bool prio_is_valid(enum v4l2_priority prio)
> >> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> >> index 68999a3..1948097 100644
> >> --- a/include/media/v4l2-dev.h
> >> +++ b/include/media/v4l2-dev.h
> >> @@ -179,6 +179,7 @@ struct video_device * __must_check video_device_alloc(void);
> >>
> >> int v4l_enable_media_tuner(struct video_device *vdev);
> >> void v4l_disable_media_tuner(struct video_device *vdev);
> >> +int v4l_vb2q_enable_media_tuner(struct vb2_queue *q);
> >
> > Documentation?
> >
> >>
> >> /* this release function frees the vdev pointer */
> >> void video_device_release(struct video_device *vdev);
>
>
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