Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759051Ab3GZOXn (ORCPT ); Fri, 26 Jul 2013 10:23:43 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:38750 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759031Ab3GZOXj (ORCPT ); Fri, 26 Jul 2013 10:23:39 -0400 Date: Fri, 26 Jul 2013 15:21:40 +0100 From: Russell King - ARM Linux To: "jonsmirl@gmail.com" Cc: David Woodhouse , Jason Cooper , Mark Rutland , "devicetree@vger.kernel.org" , "ksummit-2013-discuss@lists.linuxfoundation.org" , Ian Campbell , Pawel Moll , Stephen Warren , Richard Cochran , Domenico Andreoli , "rob.herring@calxeda.com" , "linux-kernel@vger.kernel.org" , Jason Gunthorpe , Dave P Martin , "linux-arm-kernel@lists.infradead.org" Subject: Re: [Ksummit-2013-discuss] DT bindings as ABI [was: Do we have people interested in device tree janitoring / cleanup?] Message-ID: <20130726142140.GR24642@n2100.arm.linux.org.uk> References: <51F168FC.9070906@wwwdotorg.org> <20130725182920.GA24955@e106331-lin.cambridge.arm.com> <20130725184834.GA8296@netboy> <20130725213753.GC17616@obsidianresearch.com> <20130726080115.GA5436@netboy> <1374831744.2923.42.camel@shinybook.infradead.org> <20130726130927.GC4219@netboy> <20130726132709.GH29916@titan.lakedaemon.net> <1374846070.14574.92.camel@i7.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1683 Lines: 32 On Fri, Jul 26, 2013 at 10:14:32AM -0400, jonsmirl@gmail.com wrote: > Yes, yes - that's why the schema should be written down and used as a > validation input to dtc. Then dtc can spit out errors for non-standard > items. There would be two versions - the standard one and a legacy one > that includes the standard one plus the hacks that can't be undone. > > But more importantly it provides a framework for people creating new > node definitions. Now they can't work in a vacuum and come up with > random names and structure for everything. > > Most of the problems express in the thread would go away if the schema > was written down and discussed. The rule going forward would be no new > nodes that aren't part of the standard schema. So this is why I'm seeing patches just a short time ago removing existing compatible strings from the DT descriptions and associated driver, and replacing them with new ones... meaning that the old DT files won't work with newer kernels. What that means is using the descriptions as the schema won't catch that because they're changing those as well to match. There's a solution to that: dtc becomes a separate project external to the kernel which also contains the schemas that it verifies against. That way, if you want to make changes such as that above, you need to get it past not only kernel people but also past dtc maintainers - which increases the chances of such stuff being caught. -- 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/