From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754197Ab3G2Sk6 (ORCPT ); Mon, 29 Jul 2013 14:40:58 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:41013 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834Ab3G2Sk4 (ORCPT ); Mon, 29 Jul 2013 14:40:56 -0400 Date: Mon, 29 Jul 2013 12:40:48 -0600 From: Jason Gunthorpe To: Russell King - ARM Linux Cc: Mark Rutland , "devicetree@vger.kernel.org" , "ksummit-2013-discuss@lists.linuxfoundation.org" , Samuel Ortiz , Pawel Moll , Stephen Warren , Catalin Marinas , Richard Cochran , Domenico Andreoli , "rob.herring@calxeda.com" , "linux-kernel@vger.kernel.org" , Olof Johansson , Dave P Martin , "linux-arm-kernel@lists.infradead.org" , Ian Campbell Subject: Re: DT bindings as ABI [was: Do we have people interested in device tree janitoring / cleanup?] Message-ID: <20130729184048.GE15861@obsidianresearch.com> References: <20130725175702.GC22291@e106331-lin.cambridge.arm.com> <51F168FC.9070906@wwwdotorg.org> <20130725182920.GA24955@e106331-lin.cambridge.arm.com> <20130725184834.GA8296@netboy> <20130725213753.GC17616@obsidianresearch.com> <20130726045433.GB4100@netboy> <20130726171524.GB28895@obsidianresearch.com> <20130727084825.GA4707@netboy> <20130729175400.GB15861@obsidianresearch.com> <20130729181607.GM24642@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130729181607.GM24642@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.195 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 29, 2013 at 07:16:07PM +0100, Russell King - ARM Linux wrote: > What does it take? Good practice, care, thought and planning. All > the qualities which should already be present for kernel _engineers_. > Not an "lets create something for me, I don't care about anyone else" > attitude. I agree with what you've written, but we are looking at this from different ends of the problem. I fully agree you can create a main line kernel GIT tree that has a stable DT ABI. However, I as an ODM, with time pressure, cannot wait for the kernel folks to finish this work. So from my perspective the DT will not be stable, as I will put whatever interm stuff I choose to have a shippable product. Thus I have to design my systems for an unstable DT, and the message from the kernel community to people in my posistion should be: When you ship early with non-mainlined DT schema, design your boot system around an unstable DT. Plan to migrate your DT to upstream once it becomes finalized. Here is the rub: Once I design for an unstable DT I simply don't derive value from the kernel communities work to create a stable DT. So who is getting the benefit of this work, and is it worth the cost? Jason