From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sceptre.pobox.com (sceptre.pobox.com [207.106.133.20]) by ozlabs.org (Postfix) with ESMTP id 44115DDDCA for ; Thu, 30 Aug 2007 04:12:57 +1000 (EST) Date: Wed, 29 Aug 2007 13:12:32 -0500 From: Nathan Lynch To: Joachim Fenkes Subject: Re: [PATCH 2.6.23] ibmebus: Prevent bus_id collisions Message-ID: <20070829181232.GB23140@localdomain> References: <200708291815.18197.fenkes@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <200708291815.18197.fenkes@de.ibm.com> Cc: Thomas Klein , Jan-Bernd Themann , LKML , LinuxPPC-Dev , Christoph Raisch , Paul Mackerras , Stefan Roscher List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi- Joachim Fenkes wrote: > Previously, ibmebus derived a device's bus_id from its location code. The > location code is not guaranteed to be unique, so we might get bus_id > collisions if two devices share the same location code. The OFDT full_name, > however, is unique, so we use that instead. This is a userspace-visible change, but I guess it's unavoidable. Will anything break? Also, I dislike this approach of duplicating the firmware device tree path in sysfs. Are GX/ibmebus devices guaranteed to be children of the same node in the OF device tree? If so, their unit addresses will be unique, and therefore suitable values for bus_id. I believe this is what the powerpc vio bus code does.