Messages in this thread Patch in this message | | | From | Jan Glauber <> | Subject | [PATCH v3 1/3] PCI: Allow PCI_DEV_FLAGS_NO_BUS_RESET to be used on bus device | Date | Wed, 30 Aug 2017 16:24:52 +0200 |
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From: David Daney <david.daney@cavium.com>
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 <david.daney@cavium.com> [jglauber@cavium.com: fixed typo] Signed-off-by: Jan Glauber <jglauber@cavium.com> --- 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
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