From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [GIT PULL] make mach-omap2 boot with device tree only for v3.14 Date: Tue, 10 Dec 2013 14:35:47 +0000 Message-ID: <20131210143547.GA32243@n2100.arm.linux.org.uk> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:44198 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752778Ab3LJOga (ORCPT ); Tue, 10 Dec 2013 09:36:30 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tony Lindgren Cc: arm@kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org On Mon, Dec 09, 2013 at 06:42:27PM -0800, Tony Lindgren wrote: > We can now finally make mach-omap2 to boot with device tree only and get > rid of over 20k lines of platform init code that way. > > Most basic devices already work using device tree based initialization > and the remaining devices can be initialized using platform data > with pdata-quirks.c. > > So for most missing boards it's just a question of adding a .dts file > that should be fairly similar to one of the existing .dts files as > we've tried to cover all basic omap3 board types. > > For people getting started updating their board files to for device > tree, there are some basic instructions in commit 8dc8b3ddf5d7 > (ARM: OMAP2+: Remove legacy omap3 board-*.c files and make mach-omap2 > DT only for booting). > > Please also note that there are also some related fixes making their way > into the mainline kernel that are needed for some use cases: > > PM off-idle for omap3 and wake-up events need the following two patches: While this is good, what seems to be happening is a complete switch from one method of booting to a different method of booting with no compatibility inbetween. We're going from only supporting the ATAG booting protocol for these platforms in v3.12 to only supporting the DT booting protocol in v3.13. There's no forward or backwards compatibility - it's one or the other. This is bad: this is the kind of "flag day" change which Linus hates - and I hate it because it means I need to update my build test system at the same time that arm-soc merges this stuff. This is utterly crap - it's crap not only from the point of view of the user perspective, but also from the development methodology point of view.