From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A2913B7D67 for ; Mon, 15 Mar 2010 16:51:59 +1100 (EST) Subject: Re: Problem with PCI bus rescan on 460EX From: Benjamin Herrenschmidt To: Kenji Kaneshige In-Reply-To: <4B9DC820.2060100@jp.fujitsu.com> References: <4B8E6FA3.70503@embedded-sol.com> <20100310225100.GB27324@ldl.fc.hp.com> <4B98A0CB.8090103@embedded-sol.com> <4B9A07D2.4060801@jp.fujitsu.com> <4B9AC885.3010107@embedded-sol.com> <4B9DC820.2060100@jp.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 15 Mar 2010 16:46:46 +1100 Message-ID: <1268632006.2335.10.camel@pasglop> Mime-Version: 1.0 Cc: linux-pci@vger.kernel.org, Felix Radensky , Alex Chiang , "linuxppc-dev@ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2010-03-15 at 14:39 +0900, Kenji Kaneshige wrote: > > > Yes, with these lines removed bridge memory window is properly > allocated. > > These lines are to prevent updating IO or memory windows when there > are > some devices working behind the bridge. So please note that removing > these lines is just for debugging. This is not a very good way to do so though. Many firmwares will leave those enabled even when the bridges -do- have to be reconfigured. Worse... the code means that the kernel -will- have updated its resource tree, probably assigned new resources, etc... to those bridges, and thus to devices underneath them, but will silently fail to actually update the bridge BARs to match. This seems like a major bug to me in fact. Cheers, Ben.