Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760476Ab3DCQPd (ORCPT ); Wed, 3 Apr 2013 12:15:33 -0400 Received: from mail-oa0-f52.google.com ([209.85.219.52]:44449 "EHLO mail-oa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758930Ab3DCQPc (ORCPT ); Wed, 3 Apr 2013 12:15:32 -0400 MIME-Version: 1.0 In-Reply-To: <51593E81.3030800@openvz.org> References: <20130314144936.10073.2403.stgit@zurg> <51593E81.3030800@openvz.org> From: Bjorn Helgaas Date: Wed, 3 Apr 2013 10:15:09 -0600 Message-ID: Subject: Re: [PATCH bugfix 3.9] PCI: Don't try to disable Bus Master on disconnected PCI devices To: Konstantin Khlebnikov Cc: "linux-kernel@vger.kernel.org" , "Rafael J. Wysocki" , kexec@lists.infradead.org, "Eric W. Biederman" , Jeff Garzik , Vivek Goyal , "linux-pci@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2114 Lines: 58 [+cc linux-pci] On Mon, Apr 1, 2013 at 2:00 AM, Konstantin Khlebnikov wrote: > BUMP. This is degradation from 3.8, so this patch must be in 3.9. > > I still don't like this forced clearing bus-master bit. But this hack > definitely fixes problems in kexec, so there is reason to keep it here. Applied to for-linus for v3.9, thanks! > Konstantin Khlebnikov wrote: >> >> This is fix for commit 7897e6022761ace7377f0f784fca059da55f5d71 from >> v3.9-rc1 >> ("PCI: Disable Bus Master unconditionally in pci_device_shutdown()") >> in turn that was fix for b566a22c23327f18ce941ffad0ca907e50a53d41 from >> v3.5-rc1 >> ("PCI: disable Bus Master on PCI device shutdown") >> >> Unfortunately fixing one bug uncovers another: >> ->shutdown() callback might switch device to deep sleep state. >> PCI config space no longer available after that. >> >> Link: https://lkml.org/lkml/2013/3/12/529 >> Signed-off-by: Konstantin Khlebnikov >> Reported-and-Tested-by: Vivek Goyal >> Cc: Bjorn Helgaas >> Cc: Rafael J. Wysocki >> --- >> drivers/pci/pci-driver.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c >> index 1fa1e48..79277fb 100644 >> --- a/drivers/pci/pci-driver.c >> +++ b/drivers/pci/pci-driver.c >> @@ -390,9 +390,10 @@ static void pci_device_shutdown(struct device *dev) >> >> /* >> * Turn off Bus Master bit on the device to tell it to not >> - * continue to do DMA >> + * continue to do DMA. Don't touch devices in D3cold or unknown >> states. >> */ >> - pci_clear_master(pci_dev); >> + if (pci_dev->current_state <= PCI_D3hot) >> + pci_clear_master(pci_dev); >> } >> >> #ifdef CONFIG_PM >> > -- 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/