RE: [PATCH] Support for write-only controls

["Martin Rubli" <linux1@xxxxxxxxxx>]

Hi Brandon,

> -----Original Message-----
> From: Brandon Philips [mailto:brandon@xxxxxxxx]
> Sent: Tuesday, April 15, 2008 08:44
> To: Martin Rubli; linux1@xxxxxxxxxx; Laurent Pinchart
> Cc: Linux and Kernel Video
> Subject: Re: [PATCH] Support for write-only controls
> 
> On 15:12 Wed 13 Feb 2008, Brandon Philips wrote:
> > On 01:01 Tue 18 Dec 2007, Martin Rubli wrote:
> > > Thanks a lot for all your feedback and the constructive discussion and
> sorry
> > > for the delay while I was without Internet on the weekend. I'll try to
> > > summarize what we have so far:
> > >
> > > Write-only controls:
> > >
> > > It seems, everybody likes EACCES. Michael, maybe we could get some
> feedback
> > > from you on this? It would be nice to change the spec, so that EACCES
> also
> > > becomes the error for writing read-only controls--it seems
appropriate.
> But
> > > if for some reason we can't change that we should probably make the
> > > write-only controls consistent and return EINVAL as well.
> > >
> > > Unusable controls due to device communication error:
> > >
> > > The easiest solution seems to be to set the V4L2_CTRL_FLAG_DISABLED
> flag as
> > > was suggested. The documentation currently says "permanently disabled
> and
> > > should be ignored by the application" which I think is exactly what
> applies
> > > to the situation. The V4L2_CTRL_FLAG_NEXT_CTRL would still be
> respected by
> > > drivers supporting the extended control enumeration, so no need to the
> spec
> > > is required. But I would still add a short paragraph about the first
part as
> > > a guide for future implementations and a witness of this thread. ;-)
> > >
> > > As soon as everyone agrees on this, I will propose new patches. Let me
> know
> > > what you think ...
> >
> 
> Ping.  I never saw patches come across for this.

Attached the patch for videodev2.h and the documentation sources.

Signed-off-by: Martin Rubli <linux1 rubli info>

Cheers,
Martin

Attachment: v4l2_ctrl_flag_write_only.patch
Description: Binary data

Attachment: v4l2_ctrl_flag_write_only-doc.patch
Description: Binary data

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