Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755823Ab0HaFt7 (ORCPT ); Tue, 31 Aug 2010 01:49:59 -0400 Received: from mail-gy0-f174.google.com ([209.85.160.174]:33037 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754581Ab0HaFt6 convert rfc822-to-8bit (ORCPT ); Tue, 31 Aug 2010 01:49:58 -0400 MIME-Version: 1.0 In-Reply-To: <20100830144946.5c0bce22@debxo> References: <20100628215407.2017bf2f@debian> <20100829235100.6dcedcb8@debxo> <20100830000751.2b845d05@debxo> <20100830144946.5c0bce22@debxo> From: Grant Likely Date: Mon, 30 Aug 2010 23:49:36 -0600 X-Google-Sender-Auth: e2wq-Ufm4KPy7xE_vd8so4r1Oj8 Message-ID: Subject: Re: [PATCH 9/9] x86: OLPC: add OLPC device-tree support To: Andres Salomon Cc: devicetree-discuss@lists.ozlabs.org, sparclinux@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, cjb@laptop.org, Mitch Bradley , pgf@laptop.org, linux-kernel@vger.kernel.org, davem@davemloft.net, Stephen Neuendorffer Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1959 Lines: 45 On Mon, Aug 30, 2010 at 12:49 PM, Andres Salomon wrote: > On Mon, 30 Aug 2010 12:14:57 -0600 > Grant Likely wrote: > >> On Sun, Aug 29, 2010 at 10:07 PM, Andres Salomon >> wrote: >> > >> > Make use of PROC_DEVICETREE to export the tree, and sparc's >> > PROMTREE code to call into OLPC's Open Firmware to build the tree. >> > >> > This also adds an init hook to proc_device_tree_init so that we can >> > ensure the device tree has been built prior to the proc_root_init >> > stuff attempting to populate /proc/device-tree. >> >> I'm not clear as to why this is needed. ?I would expect OLPC platform >> setup code would take care of extracting the device tree well before >> the kernel gets to setting up the representation in /proc/device-tree. >> >> g. >> > > For simplicity; the OLPC platform setup code runs very early during > boot. ?I preferred to keep that as minimal as possible, and defer > device tree allocation until the x86 mm code has finished initializing > (this skipping all the fun bootmem/etc work that'll be happening for > x86 soon). > > Of course, once it's done initializing, one can either hardcode an > olpc_init_devtree call at the end of x86's setup_arch, or we can add a > generic hook for late devtree initialization right before proc > populates /proc/device-tree. ?I chose the latter, but it could easily > be changed to the former if folks feel strongly about it. > > I would've normally just used an initcall for it, but the proc_devtree > code runs prior to any of the initcall hooks. Hmmm. I wonder if proc_devtree initialization could be deferred to an initcall. That would make the problem go away. g. -- 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/