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authorDavid Daney <david.daney@cavium.com>2017-09-08 10:10:31 +0200
committerBjorn Helgaas <bhelgaas@google.com>2017-10-11 13:26:48 -0500
commit357027786f3523d26f42391aa4c075b8495e5d28 (patch)
treea2c761dec559ef36536182767e540bbdbb66da64 /drivers/pci
parent822155100e589f2a4891b3b2db2f901824d47e69 (diff)
downloadlinux-357027786f3523d26f42391aa4c075b8495e5d28.tar.gz
PCI: Avoid bus reset if bridge itself is broken
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 <david.daney@cavium.com>
[jglauber@cavium.com: fixed typo]
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pci.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6078dfc11b11..74f1c57ab93b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4356,6 +4356,10 @@ 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)))