Re: [PATCH v4 1/2] media/v4l2-ctrls: Always run s_ctrl on volatile ctrls

From: Ricardo Ribalda Delgado
Date: Mon Mar 09 2015 - 12:45:53 EST


Hello

Back from holidays and back to this issue. Sorry for the delay.

> I'm not sure about Ricardo's use case, is it the one we've discussed on #v4l ?
> If so, and if I recall correctly, the idea was to perform an action with a
> parameter, and didn't require volatility.

In my case, there is a trigger overflow bit. The user acks the trigger
overflow by writting any value to the control.

There is no parameter. In that sense it looks like a volatile read + a
button on a controll.

> Your proposal is interesting as well, but I'm not sure about the
> V4L2_CTRL_FLAG_ACTION name. Aren't all controls supposed to have an action of
> some sort ? That's nitpicking of course.

What about the name STATELESS_WRITE ? or perhaps VOLATILE_WRITE? I
dont care about the name :), but better have it solved before I write
the doc :P

>
> Also, should the action flag be automatically set for button controls ? Button
> controls would in a way become type-less controls with the action flag set,
> that's interesting. I suppose type-less controls without the action flag don't
> make sense.

I agree!


Best regards and thanks!

--
Ricardo Ribalda
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