From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752190AbdLMCHP (ORCPT ); Tue, 12 Dec 2017 21:07:15 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:33805 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753880AbdLMCCH (ORCPT ); Tue, 12 Dec 2017 21:02:07 -0500 From: alexander.levin@verizon.com Cc: David Daney , Jan Glauber , Bjorn Helgaas , alexander.levin@verizon.com X-Host: surveyor.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 3.18 30/40] PCI: Avoid bus reset if bridge itself is broken Thread-Topic: [PATCH AUTOSEL for 3.18 30/40] PCI: Avoid bus reset if bridge itself is broken Thread-Index: AQHTc7X8iRvnOeoQykq8qHsYP6pPdA== Date: Wed, 13 Dec 2017 01:59:18 +0000 Message-ID: <20171213015905.7059-30-alexander.levin@verizon.com> References: <20171213015905.7059-1-alexander.levin@verizon.com> In-Reply-To: <20171213015905.7059-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vBD27J3m016150 From: David Daney [ Upstream commit 357027786f3523d26f42391aa4c075b8495e5d28 ] When checking to see if a PCI bus can safely be reset, we previously checked to see if any of the children had their PCI_DEV_FLAGS_NO_BUS_RESET flag set. Children marked with that flag are known not to behave well after a bus reset. Some PCIe root port bridges also do not behave well after a bus reset, sometimes causing the devices behind the bridge to become unusable. Add a check for PCI_DEV_FLAGS_NO_BUS_RESET being set in the bridge device to allow these bridges to be flagged, and prevent their secondary buses from being reset. Signed-off-by: David Daney [jglauber@cavium.com: fixed typo] Signed-off-by: Jan Glauber Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d3decb52eb7e..1563cfadeaef 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3580,6 +3580,10 @@ static bool pci_bus_resetable(struct pci_bus *bus) { struct pci_dev *dev; + + if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)) + return false; + list_for_each_entry(dev, &bus->devices, bus_list) { if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || (dev->subordinate && !pci_bus_resetable(dev->subordinate))) -- 2.11.0