From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-la0-f44.google.com ([209.85.215.44]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UMZf0-0005wl-U0 for kexec@lists.infradead.org; Mon, 01 Apr 2013 08:00:11 +0000 Received: by mail-la0-f44.google.com with SMTP id eb20so1927831lab.17 for ; Mon, 01 Apr 2013 01:00:05 -0700 (PDT) Message-ID: <51593E81.3030800@openvz.org> Date: Mon, 01 Apr 2013 12:00:01 +0400 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: [PATCH bugfix 3.9] PCI: Don't try to disable Bus Master on disconnected PCI devices References: <20130314144936.10073.2403.stgit@zurg> In-Reply-To: <20130314144936.10073.2403.stgit@zurg> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: linux-kernel@vger.kernel.org Cc: "Rafael J. Wysocki" , kexec@lists.infradead.org, "Eric W. Biederman" , Bjorn Helgaas , Jeff Garzik , Vivek Goyal 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. 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 > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec