Re: [PATCH] [media] usbtv: Add driver for Fushicai USBTV007 videoframe grabber

From: Lubomir Rintel
Date: Mon Jun 17 2013 - 10:14:03 EST


On Wed, 2013-06-12 at 09:49 +0200, Hans Verkuil wrote:
...
> > > > +static int usbtv_queryctrl(struct file *file, void *priv,
> > > > + struct v4l2_queryctrl *ctrl)
> > > > +{
> > > > + return -EINVAL;
> > > > +}
> > >
> > > Drop this ioctl. If it doesn't do anything, then don't specify it.
> >
> > It actually does something; EINVAL here for any ctrl signals there's
> > zero controls.
> >
> > When undefined, ENOTTY that is returned is considered invalid by
> > gstreamer source.
>
> What version of gstreamer are you using? Looking at the gstreamer code it
> seems that it can handle ENOTTY at least since September last year. Not handling
> ENOTTY is an application bug (there are other - rare - drivers that do not
> have any controls) and as such I really don't like seeing a workaround like
> this in a driver, especially since this seems like it should be working fine
> with the latest gstreamer.

I was using GStreamer from RHEL6. I retried with Fedora 17 and it worked
fine.

Regards,
Lubo

--
Lubomir Rintel <lkundrak@xxxxx>

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