Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751395Ab3HAGet (ORCPT ); Thu, 1 Aug 2013 02:34:49 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:42441 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750756Ab3HAGer (ORCPT ); Thu, 1 Aug 2013 02:34:47 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <51FA015E.10901@jp.fujitsu.com> Date: Thu, 01 Aug 2013 15:34:06 +0900 From: Takao Indoh User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: bhelgaas@google.com CC: rjw@sisk.pl, vgoyal@redhat.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org, kexec@lists.infradead.org, ishii.hironobu@jp.fujitsu.com, ddutile@redhat.com, bill.sumner@hp.com, alex.williamson@redhat.com, hbabu@us.ibm.com, linux-acpi@vger.kernel.org Subject: Re: [PATCH v2] PCI: Reset PCIe devices to stop ongoing DMA References: <1368509365-2260-1-git-send-email-indou.takao@jp.fujitsu.com> <51F85BCC.2070103@jp.fujitsu.com> <1699397.FXoFYIGzbk@vostro.rjw.lan> In-Reply-To: <1699397.FXoFYIGzbk@vostro.rjw.lan> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1778 Lines: 41 (2013/08/01 6:23), Rafael J. Wysocki wrote: > On Wednesday, July 31, 2013 03:08:03 PM Bjorn Helgaas wrote: >> [+cc Rafael, linux-acpi] >> >> On Tue, Jul 30, 2013 at 6:35 PM, Takao Indoh wrote: >> >>> On x86, currently IOMMU initialization run *after* PCI enumeration, but >>> what you are talking about is that it should be changed so that x86 >>> IOMMU initialization is done *before* PCI enumeration like sparc, right? >> >> Yes. I don't know whether or when that initialization order will ever >> be changed, but I do think we should avoid building more >> infrastructure that depends on the current order. >> >> Changing the order is a pretty big deal because it's a lot more than >> just the IOMMU. Basically I think we should be enumerating ACPI >> devices, including the IOMMU, before PCI devices, but there's a lot of >> legacy involved in that area. Added Rafael in case he has any >> thoughts. > > Well, actually, I'm not really familiar with IOMMUs, sorry. > > I do think that initializing IOMMU before PCI enumeration would be better, > however. At least if the ordering should be the same on all architectures, > which I suppose is the case, that's the one I'd choose. Ok guys. If x86 IOMMU maintainer also thinks changing order is necessary, maybe I need to give up device reset in kdump kernel and consider doing it in panic kernel. Either way, I need bus reset interface to reset devices. Bjorn, could you review the bus reset patches Alex posted yesterday? Thanks, Takao Indoh -- 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/