From: David Daney david.daney@cavium.com
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ 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 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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 409f895b5a3d..ffd8fe77b8ae 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3651,6 +3651,10 @@ 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)))