From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752291Ab2DVPwN (ORCPT ); Sun, 22 Apr 2012 11:52:13 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:42433 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752142Ab2DVPwL (ORCPT ); Sun, 22 Apr 2012 11:52:11 -0400 Date: Sun, 22 Apr 2012 23:52:02 +0800 From: Richard Yang To: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: One problem in reassign pci bus number? Message-ID: <20120422155202.GA13540@richard> Reply-To: Richard Yang References: <20120410090306.GA7056@richard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120410090306.GA7056@richard> User-Agent: Mutt/1.5.21 (2010-09-15) x-cbid: 12042215-5816-0000-0000-0000023DB204 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All, I am reading the pci_scan_bridge() and not sure what will happen in following situation. Suppose the kernel is not passed the pci=assign-busses. Below is a picture about the pci system. +-------+ | | root bridge(0,255) +---+---+ | Bus 0 -----+-----------+------------------------------+-- | | | | | | +----+----+ +-----+-----+ | | B1(1,15) | |B2(16,28) +----+----+ +-----+-----+ | Bus 1 | Bus 16 -----+----------------------- ----------+---------------- | +----+----+ | | B3 +---------+ Suppose B1 and B2 works fine with the BIOS, which get the right bus number and range. B3 does not works fine with the BIOS, which doesn't get the bus number. So in pci_scan_bridge(), B3 will be met in the second pass and get bus number 16? Would this be a conflict? -- Richard Yang Help you, Help me