From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Jan Glauber To: Bjorn Helgaas , linux-pci@vger.kernel.org, Alex Williamson 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> In-Reply-To: <1502957663-5527-1-git-send-email-jglauber@cavium.com> References: <1502957663-5527-1-git-send-email-jglauber@cavium.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm@vger.kernel.org, david.daney@cavium.com, Jon Masters , linux-kernel@vger.kernel.org, Robert Richter , Jan Glauber , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel