> -----Original Message-----
> From: Hans Verkuil [mailto:[email protected]]
> Sent: Friday, November 06, 2009 12:03 PM
> To: Hiremath, Vaibhav
> Cc: [email protected]
> Subject: Re: [PATCH V2] Davinci VPFE Capture: Add support for
> Control ioctls
>
> On Friday 06 November 2009 06:30:42 Hiremath, Vaibhav wrote:
> > > -----Original Message-----
> > > From: [email protected] [mailto:linux-media-
> > > [email protected]] On Behalf Of Hans Verkuil
> > > Sent: Thursday, November 05, 2009 9:48 PM
> > > To: Hiremath, Vaibhav
> > > Cc: [email protected]
> > > Subject: Re: [PATCH V2] Davinci VPFE Capture: Add support for
> > > Control ioctls
> > >
> > > On Thursday 29 October 2009 07:51:04 [email protected] wrote:
<snip>
> > >
> > > Please remove this bogus flag. Just do:
> > >
> > [Hiremath, Vaibhav] Hans, while implementing this ioctl I was also
> thinking the same, but v4l2_ctrl_check do check this flag and also
> in V4L2 spec it has been mentioned that
> > "This control is permanently disabled and should be ignored by the
> application."
> >
> > So I thought this may be useful for standard applications, we
> still have some drivers do use this flag actually.
>
> The use of this flag is for very specific cases as is documented in
> a footnote
> in the v4l2 spec:
>
> "V4L2_CTRL_FLAG_DISABLED was intended for two purposes: Drivers can
> skip predefined
> controls not supported by the hardware (although returning EINVAL
> would do as well),
> or disable predefined and private controls after hardware detection
> without the
> trouble of reordering control arrays and indices (EINVAL cannot be
> used to skip
> private controls because it would prematurely end the enumeration)."
>
> In both cases you would only check for this flag if queryctrl
> returns 0, so
> setting the flag AND returning an error is unnecessary.
>
[Hiremath, Vaibhav] Make sense. I will update the patch and submit it again.
Thanks,
Vaibhav
> Regards,
>
> Hans
>
> >
> > Thanks,
> > Vaibhav
> >
> > > return v4l2_device_call_until_err(&vpfe_dev->v4l2_dev, sdinfo-
> > > >grp_id,
> > > core, queryctrl, qctrl);
> > >
> > > Simple and effective.
> > >
> > > Regards,
> > >
> > > Hans
> > >
> > > > +
> > > > + return ret;
> > > > +}
> > > > +
> > > > +static int vpfe_g_ctrl(struct file *file, void *priv, struct
> > > v4l2_control *ctrl)
> > > > +{
> > > > + struct vpfe_device *vpfe_dev = video_drvdata(file);
> > > > + struct vpfe_subdev_info *sdinfo;
> > > > +
> > > > + sdinfo = vpfe_dev->current_subdev;
> > > > +
> > > > + return v4l2_device_call_until_err(&vpfe_dev->v4l2_dev,
> sdinfo-
> > > >grp_id,
> > > > + core, g_ctrl, ctrl);
> > > > +}
> > > > +
> > > > +static int vpfe_s_ctrl(struct file *file, void *priv, struct
> > > v4l2_control *ctrl)
> > > > +{
> > > > + struct vpfe_device *vpfe_dev = video_drvdata(file);
> > > > + struct vpfe_subdev_info *sdinfo;
> > > > +
> > > > + sdinfo = vpfe_dev->current_subdev;
> > > > +
> > > > + return v4l2_device_call_until_err(&vpfe_dev->v4l2_dev,
> sdinfo-
> > > >grp_id,
> > > > + core, s_ctrl, ctrl);
> > > > +}
> > > > +
> > > > /*
> > > > * Videobuf operations
> > > > */
> > > > @@ -1939,6 +1979,9 @@ static const struct v4l2_ioctl_ops
> > > vpfe_ioctl_ops = {
> > > > .vidioc_querystd = vpfe_querystd,
> > > > .vidioc_s_std = vpfe_s_std,
> > > > .vidioc_g_std = vpfe_g_std,
> > > > + .vidioc_queryctrl = vpfe_queryctrl,
> > > > + .vidioc_g_ctrl = vpfe_g_ctrl,
> > > > + .vidioc_s_ctrl = vpfe_s_ctrl,
> > > > .vidioc_reqbufs = vpfe_reqbufs,
> > > > .vidioc_querybuf = vpfe_querybuf,
> > > > .vidioc_qbuf = vpfe_qbuf,
> > > > --
> > > > 1.6.2.4
> > > >
> > > > --
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> > > >
> > >
> > >
> > >
> > > --
> > > Hans Verkuil - video4linux developer - sponsored by TANDBERG
> Telecom
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-
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> >
> >
> >
>
>
>
> --
> Hans Verkuil - video4linux developer - sponsored by TANDBERG Telecom
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