PCI: Don't try to restore VF BARs
VF BARs are read-only zero, so updating VF BARs will not have any effect.
See the SR-IOV spec r1.1, sec 3.4.1.11.
Don't update VF BARs in pci_restore_bars().
This avoids spurious "BAR %d: error updating" messages that we see when
doing vfio pass-through after 6eb7018705de ("vfio-pci: Move idle devices to
D3hot power state").
[bhelgaas: changelog, fix whitespace]
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6a9a111..1cfb47a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -484,7 +484,7 @@
}
/**
- * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
+ * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
* @dev: PCI device to have its BARs restored
*
* Restore the BAR values for a given device, so as to make it
@@ -494,6 +494,10 @@
{
int i;
+ /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
+ if (dev->is_virtfn)
+ return;
+
for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
pci_update_resource(dev, i);
}