Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756571Ab0H3S2I (ORCPT ); Mon, 30 Aug 2010 14:28:08 -0400 Received: from LUNGE.MIT.EDU ([18.54.1.69]:58183 "EHLO lunge.queued.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756537Ab0H3S2G (ORCPT ); Mon, 30 Aug 2010 14:28:06 -0400 Date: Mon, 30 Aug 2010 14:49:46 -0400 From: Andres Salomon To: Grant Likely 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 Subject: Re: [PATCH 9/9] x86: OLPC: add OLPC device-tree support Message-ID: <20100830144946.5c0bce22@debxo> In-Reply-To: References: <20100628215407.2017bf2f@debian> <20100829235100.6dcedcb8@debxo> <20100830000751.2b845d05@debxo> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.20.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1712 Lines: 39 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. -- 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/