Re: [Ksummit-discuss] [TECH TOPIC] Addressing complex dependencies and semantics (v2)

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Thursday 28 Jul 2016 08:18:08 Mauro Carvalho Chehab wrote:
> Em Wed, 27 Jul 2016 09:50:04 -0700 Luis R. Rodriguez escreveu:
> > (first e-mail bounced)
> > 
> > Rafael has proposed has a set of patches to help deal with functional
> > dependencies between devices to help with power management. Mauro has
> > spoken briefly before over the media controller feature graph used to help
> > build relationship between complex dynamic dependencies.
> 
> Actually, there are two separate at the media subsystem:
> 
> 1) the complex dependencies at the build system, required by the media
> devices, as almost all media hardware require multiple drivers in order to
> work. The media controller is unrelated to it.
> 
> We have right now a very complex Kconfig setup, as we try to map what
> user wants (a driver for the board "foo") with the requirements that
> such "foo" device requires (e. g. tuner "bar", demod "foobar",
> main driver "foodriver", etc).
> 
> 2) the complexity of setting up pipelines using the media controller.
> 
> The media controller reflects the complexity of the media devices,
> showing their internal topology and allowing userspace to dynamically
> re-route the pipelines. There are several such pipeline examples,
> obtained from real hardware at:
> 	https://mchehab.fedorapeople.org/mc-next-gen/
> 
> Internally, the media controller has a logic to do graph traversal,
> in order to setup such pipelines. As the idea is to use SAT for the
> build system, eventually we could re-use its code inside the media
> controller, in order to improve the media controller logic, if such
> code find its way into the Kernel itself.

I'm not sure to follow you there. How would an SAT solver help the media 
controller ?

> So, I'm very interested on this topic.

-- 
Regards,

Laurent Pinchart