Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933925AbdLVJD0 (ORCPT ); Fri, 22 Dec 2017 04:03:26 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:39532 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933825AbdLVJDS (ORCPT ); Fri, 22 Dec 2017 04:03:18 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Daney , Jan Glauber , Bjorn Helgaas , Alex Williamson , Sasha Levin Subject: [PATCH 4.14 110/159] PCI: Avoid bus reset if bridge itself is broken Date: Fri, 22 Dec 2017 09:46:35 +0100 Message-Id: <20171222084629.675964715@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171222084623.668990192@linuxfoundation.org> References: <20171222084623.668990192@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1588 Lines: 47 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4356,6 +4356,10 @@ static bool pci_bus_resetable(struct pci { 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)))