Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751427Ab0K2THq (ORCPT ); Mon, 29 Nov 2010 14:07:46 -0500 Received: from am1ehsobe001.messaging.microsoft.com ([213.199.154.204]:21586 "EHLO AM1EHSOBE001.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266Ab0K2THo (ORCPT ); Mon, 29 Nov 2010 14:07:44 -0500 X-SpamScore: -12 X-BigFish: VS-12(zz936eK1432N98dNa3c1kzz1202hzz8275dhz2dh2a8h691h668h67dh61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: KIP:(null);UIP:(null);IPVD:NLI;H:de01egw02.freescale.net;RD:de01egw02.freescale.net;EFVD:NLI Date: Mon, 29 Nov 2010 13:07:20 -0600 From: Scott Wood To: Benjamin Herrenschmidt CC: Sebastian Andrzej Siewior , , , , Subject: Re: [PATCH 03/11] x86/dtb: Add a device tree for CE4100 Message-ID: <20101129130720.7d060e1c@udp111988uds.am.freescale.net> In-Reply-To: <1290984809.32570.208.camel@pasglop> References: <1290706801-7323-1-git-send-email-bigeasy@linutronix.de> <1290706801-7323-4-git-send-email-bigeasy@linutronix.de> <1290808645.32570.158.camel@pasglop> <20101128160449.GC30784@www.tglx.de> <1290984809.32570.208.camel@pasglop> X-Mailer: Claws Mail 3.7.4 (GTK+ 2.20.1; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 29 Nov 2010 19:08:40.0670 (UTC) FILETIME=[D57EA7E0:01CB8FF8] X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1660 Lines: 41 On Mon, 29 Nov 2010 09:53:29 +1100 Benjamin Herrenschmidt wrote: > On Sun, 2010-11-28 at 17:04 +0100, Sebastian Andrzej Siewior wrote: > > >> + isa@legacy { What is "@legacy"? I don't think I've seen that in a unit address before, googling only turns up this device tree, and a quick grep through the ISA and base OF specs turns up nothing. > > >> + device_type = "isa"; > > >> + compatible = "simple-bus"; > > > > > >What does "simple-bus" means ? > > I added simple bus in order to get probed. But I now I rember that this > > is also supported per device_type. I get rid of it. > > device_type is a nasty bugger, we are trying to get rid of Linux > reliance on it. > > Things like "simple-bus" don't rock my boat either, it's adding to the > device-tree "informations" that are specific to the way Linux will > interpret it, which is not how it should be. The motivation for simple-bus comes from Linux, but its definition is OS-neutral. It indicates that no special bus knowledge is required to access the devices under it. I don't think it applies to ISA, though -- I/O space is special bus knowledge, and the "ranges" looks weird for memory-space as well. If we're going to get rid of device_type here, it would be nice to have some other way to indicate that this node follows the ISA binding, without having to recognize an implementation-specific compatible. -Scott -- 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/