Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754246Ab2EDJcr (ORCPT ); Fri, 4 May 2012 05:32:47 -0400 Received: from lebrac.rtp-net.org ([88.191.135.105]:40083 "EHLO lebrac.rtp-net.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753256Ab2EDJcq (ORCPT ); Fri, 4 May 2012 05:32:46 -0400 X-Greylist: delayed 489 seconds by postgrey-1.27 at vger.kernel.org; Fri, 04 May 2012 05:32:46 EDT From: Arnaud Patard (Rtp) To: Russell King - ARM Linux Cc: Arnd Bergmann , Kukjin Kim , linaro-dev@lists.linaro.org, Jason Cooper , Nicolas Pitre , Tony Lindgren , Nicolas Ferre , Linus Walleij , Magnus Damm , linux-kernel@vger.kernel.org, Haojian Zhuang , Deepak Saxena , Olof Johansson , David Brown , shawn.guo@linaro.org, Jean-Christophe PLAGNIOL-VILLARD , Sascha Hauer , linux-arm-kernel@lists.infradead.org Subject: Re: Making ARM multiplatform kernels DT-only? Organization: RtpNet References: <201205031350.35476.arnd@arndb.de> <20120503141853.GC897@n2100.arm.linux.org.uk> Date: Fri, 04 May 2012 11:22:55 +0200 In-Reply-To: <20120503141853.GC897@n2100.arm.linux.org.uk> (Russell King's message of "Thu, 3 May 2012 15:18:53 +0100") Message-ID: <87fwbg8fm8.fsf@lebrac.rtp-net.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1926 Lines: 42 Russell King - ARM Linux writes: Hi, > On Thu, May 03, 2012 at 01:50:35PM +0000, Arnd Bergmann wrote: >> My feeling is that we should just mandate DT booting for multiplatform >> kernels, because it significantly reduces the combinatorial space >> at compile time, avoids a lot of legacy board files that we cannot >> test anyway, reduces the total kernel size and gives an incentive >> for people to move forward to DT with their existing boards. > > On this point, I strongly object, especially as I'm one who uses the > existing non-DT multiplatform support extensively. It's really not > a problem for what you're trying to achieve. > Please, don't do this. afaik, the idea was to reduce the numbers of kernel to deal with. Unfortunately, this kind of restriction would increase it. Consider orion platforms. This would mean having to deal with 4 kernels (1 for DT, 1 for orion5x, 1 for kirkwood, 1 for mv78xx0). Dropping HW support because one wants to encourage people to convert their board file into DT seems weird. Doing this, imho, should even be called a regression. The DT conversion won't happen in an eye blink so non-DT kernels are still something we should take care of. > I think what you're proposing is a totally artificial restriction. > There's no problem with a kernel supporting DT and non-DT together. > We've proven that many many times. I prove it _every_ night that my > build and boot system runs - the OMAP LDP boots a multiplatform kernel > just fine without DT. I think it's true for imx too. iirc, one can build a single image for armv4/armv5 and one other for armv6/armv7 without having to use DT. Regards, Arnaud -- 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/