Re: Correct way to do s_ctrl ioctl taking into account subdev framework?

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Em 27-06-2010 00:26, Devin Heitmueller escreveu:
> On Sat, Jun 26, 2010 at 9:34 PM, Mauro Carvalho Chehab
> <mchehab@redhat.com> wrote:
>> would do the trick. Yet, the application is broken, as it is considering a positive
>> return as an error. A positive code should never be considered as an error. So, we
>> need to fix v4l2-ctl as well (ok, returning 1 is wrong as well, as this is a non-v4l2
>> compliance in this case).
> 
> A strict interpretation of the spec would read that returning zero is
> success, -1 is an well-formed error condition, and *ANYTHING* else is
> a violation of the spec and an application used for testing compliance
> should complain very loudly (which is exactly what it does).
> 
> In effect, the only patch I would consider valid for v4l2-ctl would be
> one that makes the error even more LOUD than it already is.

It should output it as an API violation, not as a failure on setting the value.
That's said, I think that a few ioctl calls used to return positive values under
certain special conditions. Not sure if this is a non-compliance or if the 
API allows it.

Cheers,
Mauro