PCI: Check IORESOURCE_UNSET before updating BAR

Check to make sure we don't update a BAR with an address we haven't
assigned.

If we haven't assigned an address to a resource, we shouldn't write it to a
BAR.  This isn't a problem for the usual path via pci_assign_resource(),
which clears IORESOURCE_UNSET before calling pci_update_resource(), but
paths like pci_restore_bars() can call this for resources we haven't
assigned.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 725d5b28398c..7f7652176fc5 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -44,6 +44,9 @@ void pci_update_resource(struct pci_dev *dev, int resno)
         if (!res->flags)
                 return;
 
+        if (res->flags & IORESOURCE_UNSET)
+                return;
+
         /*
          * Ignore non-moveable resources.  This might be legacy resources for
          * which no functional BAR register exists or another important