Re: [PATCH 2/8] [media] v4l2-async: call registered_async after subdev registration

From: Sakari Ailus
Date: Thu Aug 11 2016 - 07:18:30 EST


On Thu, Aug 11, 2016 at 02:10:43PM +0300, Sakari Ailus wrote:
> Hi Javier,
>
> On Fri, Feb 05, 2016 at 04:09:52PM -0300, Javier Martinez Canillas wrote:
> > V4L2 sub-devices might need to do initialization that depends on being
> > registered with a V4L2 device. As an example, sub-devices with Media
> > Controller support may need to register entities and create pad links.
> >
> > Execute the registered_async callback after the sub-device has been
> > registered with the V4L2 device so the driver can do any needed init.
> >
> > Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
> > ---
> >
> > drivers/media/v4l2-core/v4l2-async.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> > index 5bada202b2d3..716bfd47daab 100644
> > --- a/drivers/media/v4l2-core/v4l2-async.c
> > +++ b/drivers/media/v4l2-core/v4l2-async.c
> > @@ -119,6 +119,13 @@ static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
> > return ret;
> > }
> >
> > + ret = v4l2_subdev_call(sd, core, registered_async);
> > + if (ret < 0) {
> > + if (notifier->unbind)
> > + notifier->unbind(notifier, sd, asd);
> > + return ret;
> > + }
> > +
> > if (list_empty(&notifier->waiting) && notifier->complete)
> > return notifier->complete(notifier);
>
> I noticed this just now but what do you need this and the next patch for?
>
> We already have a callback for the same purpose: it's
> v4l2_subdev_ops.internal_ops.registered(). And there's similar
> unregistered() callback as well.
>
> Could you use these callbacks instead?
>
> What made me notice this is because the two patches break all other drivers
> that do not implement registered_async(). This would be fixed by your
> follow-up patch which is not merged, but the real question is: are these
> patches needed to begin with?

Ah, it's actually merged now. So all is well. The question still remains.
:-)

--
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx