Re: [PATCH 07/14] media: soc-camera: support deferred probing of clients

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

On Wed, 10 Apr 2013, Barry Song wrote:

> 2013/4/10 Guennadi Liakhovetski <g.liakhovetski@gmx.de>:
> > On Wed, 10 Apr 2013, Barry Song wrote:

[snip]

> >> > This cannot work, because some I2C devices, e.g. sensors, need a clock
> >> > signal from the camera interface to probe. Before the bridge driver has
> >> > completed its probing and registered a suitable clock source with the
> >> > v4l2-clk framework, sensors cannot be probed. And no, we don't want to
> >> > fake successful probing without actually being able to talk to the
> >> > hardware.
> >>
> >> i'd say same dependency also exists on ASoC.  a "fake" successful
> >> probing doesn't mean it should really begin to work if there is no
> >> external trigger source.  ASoC has successfully done that by a machine
> >> driver to connect all DAI.
> >> a way is we put all things ready in their places, finally we connect
> >> them together and launch the whole hardware flow.
> >>
> >> anyway, if you have maken the things work by some simple hacking and
> >> that means minimial changes to current soc-camera, i think we can
> >> follow.
> >
> > If you want to volunteer to step up as a new soc-camera maintainer to
> > replace my simple hacking with your comprehencive and advanced designs -
> > feel free, I'll ack straight away.
> 
> i am not sure whether you agree the new way or not. if you also agree
> this is a better way,

In fact I don't.

> i think we can do something to move ahead. i
> need sync and get input from you expert :-)

I suggest you read all the mailing list discussions of these topics over 
last months / years, conference discussion protocols instead of restarting 
a beaten to death topic at the v8 time-frame.

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/