> On Mon, Mar 1, 2010 at 4:58 AM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
>> New private controls should not use V4L2_CID_PRIVATE_BASE at all. That
>> mechanism was a really bad idea. Instead a new control should be added
>> to
>> the appropriate control class and with a offset >= 0x1000. See for
>> example
>> the CX2341X private controls in videodev2.h.
>
> So, you're suggesting that the following patch then is going to be
> NAK'd and that I'm going to have to go back and convert saa7115 to
> support the extended controls API, extend the em28xx driver to support
> the extended controls API, and retest with all the possible
> applications given how they might potentially be attempting to
> implement the rather poorly documented interface?
I have a lot to say on this subject, but unfortunately I'm swamped with
work at the moment. I'll get back to you on this tomorrow.
Regards,
Hans
>
> http://kernellabs.com/hg/~dheitmueller/em28xx-test/rev/a7d50db75420
>
> And exactly what "class" of extended controls should I use for video
> decoders? It would seem that a video decoder doesn't really fall into
> any of the existing categories - "Old-style user controls", "MPEG
> compression controls", "Camera controls", or "FM modulator controls".
> Are we saying that now I'm also going to be introducing a whole new
> class of control too?
>
>> The EXT_G/S_CTRLS ioctls do not accept PRIVATE_BASE because I want to
>> force driver developers to stop using PRIVATE_BASE. So only G/S_CTRL
>> will
>> support controls in that range for backwards compatibility.
>
> While we're on the topic, do you see any problem with the proposed fix
> for the regression you introduced?:
>
> http://kernellabs.com/hg/~dheitmueller/em28xx-test/rev/142ae5aa9e8e
>
> Between trying to figure out what the expected behavior is supposed to
> be (given the complete lack of documentation on how private controls
> are expected to be implemented in the extended controls API) and
> isolating and fixing the regression, it's hard not to be a little
> irritated at this situation. This was supposed to be a very small
> change - a single private control to a mature driver. And now it
> seems like I'm going to have to extend the basic infrastructure in the
> decoder driver, the bridge driver, add a new class of controls, all so
> I can poke one register?
>
> Devin
>
> --
> Devin J. Heitmueller - Kernel Labs
> http://www.kernellabs.com
>
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG Telecom
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