Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750810AbWCHF1c (ORCPT ); Wed, 8 Mar 2006 00:27:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751515AbWCHF1c (ORCPT ); Wed, 8 Mar 2006 00:27:32 -0500 Received: from dsl093-040-174.pdx1.dsl.speakeasy.net ([66.93.40.174]:50850 "EHLO aria.kroah.org") by vger.kernel.org with ESMTP id S1750810AbWCHF1c (ORCPT ); Wed, 8 Mar 2006 00:27:32 -0500 Date: Tue, 7 Mar 2006 21:27:23 -0800 From: Greg KH To: Tejun Heo Cc: Jeff Garzik , Kumar Gala , Linux Kernel , linux-pci@atrey.karlin.mff.cuni.cz Subject: Re: proper way to assign fixed PCI resources to a "hotplug" device Message-ID: <20060308052723.GD29867@kroah.com> References: <4408CEC8.7040507@garzik.org> <20060308020028.GB26028@kroah.com> <440E4203.7040303@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <440E4203.7040303@gmail.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1652 Lines: 43 On Wed, Mar 08, 2006 at 11:31:31AM +0900, Tejun Heo wrote: > Greg KH wrote: > >On Fri, Mar 03, 2006 at 06:18:32PM -0500, Jeff Garzik wrote: > > > >>I have a similar situation: > >> > >>BIOS initializes PCI device to mode A, I need to switch it to mode B. > >>To do this, I must assign a value to an MMIO PCI BAR that was not > >>initialized at boot. > >> > >>How to do this? > > > > > >I really don't know, what kind of device wants to do this? > > > > Jeff is probably talking about ABAR of ICH controllers. ABAR (AHCI BAR, > memory mapped IO region covering all AHCI registers) isn't needed for > IDE mode operation and the BAR register is disabled when the chip is in > IDE mode. However, ABAR becomes necessary for 1. accessing SCR registers > (for SATA phy monitor and control) or 2. switching on AHCI mode manually > (some notebook BIOSes always initalize ICH6/7m's into IDE mode even when > the controller does support AHCI mode. > > So, the problem is that the chip actually disables the PCI BAR if > certain switches aren't turned on and thus BIOSes are likely not to > reserve mmio address for the BAR. We can turn on proper switches during > driver initialization but we don't know how to wiggle the BAR into mmio > address space. Thanks for the explaination, that makes more sense. Unfortunatly I do not know how to do this right now :( Anyone with any ideas? thanks, greg k-h - 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/