From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.177]) by ozlabs.org (Postfix) with ESMTP id 8F93CDE0A6 for ; Wed, 20 May 2009 02:12:22 +1000 (EST) From: Arnd Bergmann To: linuxppc-dev@ozlabs.org Subject: Re: Musings on PCI busses Date: Tue, 19 May 2009 18:12:02 +0200 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200905191812.03347.arnd@arndb.de> Cc: Roderick Colenbrander , John Linn List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tuesday 19 May 2009, Grant Likely wrote: > 1) Probe the host controller in an of_platform driver. =A0This has the > advantage of simplicity. =A0The probe routine will get automatically > called when the PCI host controller device tree node is registered > with the of_platform bus. =A0The bus parenthood also gets reflected in > the device model and sysfs. =A0The disadvantage is that it defers PCI > bus probing until after the of_platform bus is probed (maybe this is > okay; maybe this already happens anyway). This is also what we do on 64-bit systems (well, Cell at this time). There are no fundamental problems with this, just some slightly unexpected interactions e.g. when you have use a PCI serial port as your console before probing PCI. Making CONFIG_PPC_OF_PLATFORM_PCI probably requires some more consolidation between pci_32.c and pci_64.c, but I'd consider this a good thing. Arnd <><