| Message ID | 20170516001736.4001-2-david.daney@cavium.com |
|---|---|
| State | Accepted |
| Headers | show |
Hi, On 16/05/2017 02:17, David Daney wrote: > 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 know not to behave well after a bus reset. nit: s/know/known > > 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> Thanks Eric > --- > drivers/pci/pci.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index b01bd5b..b64e4d1 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4318,6 +4318,10 @@ 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))) >
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b01bd5b..b64e4d1 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4318,6 +4318,10 @@ 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)))
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 know 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> --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+)