Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758351Ab3GZLi1 (ORCPT ); Fri, 26 Jul 2013 07:38:27 -0400 Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:39857 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752425Ab3GZLiU (ORCPT ); Fri, 26 Jul 2013 07:38:20 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 72.84.113.162 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX1+x7XYqMr6lTChzUi/uNn33Yshapq7WsBU= Date: Fri, 26 Jul 2013 07:38:09 -0400 From: Jason Cooper To: "jonsmirl@gmail.com" Cc: Russell King - ARM Linux , Linus Torvalds , Grant Likely , Rob Herring , Olof Johansson , "devicetree@vger.kernel.org" , "ksummit-2013-discuss@lists.linuxfoundation.org" , Samuel Ortiz , Catalin Marinas , Domenico Andreoli , "linux-kernel@vger.kernel.org" , Dave P Martin , "linux-arm-kernel@lists.infradead.org" Subject: Re: DT bindings as ABI [was: Do we have people interested in device tree janitoring / cleanup?] Message-ID: <20130726113809.GB29916@titan.lakedaemon.net> References: <20130725193135.GT23879@titan.lakedaemon.net> <20130725231848.GJ24642@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3638 Lines: 74 On Thu, Jul 25, 2013 at 08:27:15PM -0400, jonsmirl@gmail.com wrote: > On Thu, Jul 25, 2013 at 7:18 PM, Russell King - ARM Linux > wrote: > > On Thu, Jul 25, 2013 at 03:31:35PM -0400, Jason Cooper wrote: > >> On Thu, Jul 25, 2013 at 02:11:31PM -0500, Rob Herring wrote: > >> > On Thu, Jul 25, 2013 at 11:09 AM, Olof Johansson wrote: > >> > >> > > One problem that needs to be solved is obviously how a binding > >> > > graduates from tentative to locked. This work isn't going to be very > >> > > interesting to most people, I suspect. Think standards committee type > >> > > work. > >> > > >> > I think a time based stabilization period would be better than a > >> > separate directory to apply bindings too. Or time plus periodic review > >> > perhaps. > >> > >> The only problem with a time-based versus separate directory is how do > >> users who've downloaded the tree determine which bindings are stable? > >> If they pull a tarball, or receive an SDK, there is most likely no git > >> history attached. > >> > >> I think the idea of a 'tentative' directory (or 'locked') is churnish, > >> but necessary. If I DL'd a tarball and had to type 'tentative' to get > >> to the binding doc I wanted, that would be a pretty clear clue to be > >> delicate about how I trust/use/plan with that binding. > > > > It's actually extremely simple. If the bindings are in development, > > they must not appear in a -final released kernel. Anything that appears > > in a -final kernel becomes part of the ABI at that point. > > > > That obviously does not mean you remove them in the last -rc and put > > them back during the merge window! > > > > That's how we handle every other ABI thing in the kernel tree, why should > > DT files be any different? (I've added Linus and Grant to this discussion.) > > > > As I've already stated, it is intended to eventually remove the DT files > > from the kernel tree and have them as a separately maintained project, > > which means they will be independent of the kernel version. > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > Having a schema system for the device trees is closely related to this > discussion. In this case the schema would probably be equal to the > stable set of nodes. This has been discussed before on the device tree > mailing list. The dtc compiler would take this schema and validate the > trees it compiles against it issuing warnings for 'non-standard' > usage. Over time the schema would be updated to allow these usages > when everyone agrees to it. Note that there would be a single schema > describing all possible legal Linux device trees. s/Linux// ? > The scheme is also quite useful for new tree developers since it will > show them the universe of device tree attributes that have already > been standardized. By using comments, you could probably turn the > device tree documentation into the schema source files. One more note on schema, since DT is a description of hardware, it would be useful to have two comments, a url to the datasheet, and a canonical name of the datasheet suitable for $searchengine. Where available, of course. thx, Jason. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/