Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752337AbdHQIQb (ORCPT ); Thu, 17 Aug 2017 04:16:31 -0400 Received: from mail-wr0-f195.google.com ([209.85.128.195]:34738 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055AbdHQIPE (ORCPT ); Thu, 17 Aug 2017 04:15:04 -0400 From: Jan Glauber To: Bjorn Helgaas , linux-pci@vger.kernel.org, Alex Williamson Cc: linux-kernel@vger.kernel.org, david.daney@cavium.com, Jon Masters , Robert Richter , linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, Jan Glauber Subject: [PATCH v2 1/3] PCI: Allow PCI_DEV_FLAGS_NO_BUS_RESET to be used on bus device Date: Thu, 17 Aug 2017 10:14:21 +0200 Message-Id: <1502957663-5527-2-git-send-email-jglauber@cavium.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1502957663-5527-1-git-send-email-jglauber@cavium.com> References: <1502957663-5527-1-git-send-email-jglauber@cavium.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1343 Lines: 39 From: David Daney When checking to see if a PCI bus can safely be reset, we check to see if any of the children have their PCI_DEV_FLAGS_NO_BUS_RESET flag set. As these devices 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 the PCI_DEV_FLAGS_NO_BUS_RESET flag being set in the bridge device to allow these bridges to be flagged, and prevent their buses from being reset. A follow on patch will add a quirk for this type of bridge. Signed-off-by: David Daney [jglauber@cavium.com: fixed typo] Signed-off-by: Jan Glauber --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index af0cc34..d9abbc9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4290,6 +4290,10 @@ 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))) -- 2.9.0.rc0.21.g7777322