From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 94A2A7AA for ; Thu, 28 Jul 2016 11:24:39 +0000 (UTC) Received: from galahad.ideasonboard.com (galahad.ideasonboard.com [185.26.127.97]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D872BA9 for ; Thu, 28 Jul 2016 11:24:38 +0000 (UTC) From: Laurent Pinchart To: ksummit-discuss@lists.linuxfoundation.org Date: Thu, 28 Jul 2016 14:24:49 +0300 Message-ID: <1591503.qrDIUm0YXt@avalon> In-Reply-To: <20160728081808.08d8941e@recife.lan> References: <20160728081808.08d8941e@recife.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: Mauro Carvalho Chehab , "vegard.nossum@gmail.com" , "rafael.j.wysocki" , Marek Szyprowski , Valentin Rothberg Subject: Re: [Ksummit-discuss] [TECH TOPIC] Addressing complex dependencies and semantics (v2) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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