Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261540AbUKOIBW (ORCPT ); Mon, 15 Nov 2004 03:01:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261545AbUKOIBW (ORCPT ); Mon, 15 Nov 2004 03:01:22 -0500 Received: from colo.lackof.org ([198.49.126.79]:60322 "EHLO colo.lackof.org") by vger.kernel.org with ESMTP id S261540AbUKOIBR (ORCPT ); Mon, 15 Nov 2004 03:01:17 -0500 Date: Mon, 15 Nov 2004 01:01:16 -0700 From: Grant Grundler To: Michael Chan Cc: Grant Grundler , Andi Kleen , linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, akpm@osdl.org, greg@kroah.com, "Durairaj, Sundarapandian" Subject: Re: [PATCH] pci-mmconfig fix for 2.6.9 Message-ID: <20041115080116.GA5793@colo.lackof.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.28i X-Home-Page: http://www.parisc-linux.org/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1375 Lines: 40 On Sun, Nov 14, 2004 at 11:07:13PM -0800, Michael Chan wrote: > Grant Grundler wrote: > > > There are two tests in arch/i386/pci/mmconfig.c:pci_mmcfg_init() before > > the raw_pci_ops is set to &pci_mmcfg. Perhaps some additional crude tests > > could select a different set of pci_raw_ops to deal with posted writes > > to mmconfig space. Someone more familiar with those chipsets might > > find a more elegant solution. > > Do you mean something like pci_mmcfg1 for Intel chipsets that implement > non-posted mmconfig and pci_mmcfg2 for other chipsets that may implement > posted mmconfig? Yes. > pci_mmcfg2's write method will guarantee that the write has reached > the target before returning. If pci_mmcfg2's write method uses read > from the target to flush the write, we are back to the original problem > of out-of-spec read when writing the PMCSR register. If the flush does > not require reading from the target device, then it's fine. Yes - agreed. I do expect chip designers are aware of this problem. It's not a new problem. But it's certainly possible some are not. :^( thanks, grant > > Michael > > > - 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/