PCI: do not enable bridges more than once

In preparation for PCI core hotplug, we need to ensure that we do
not attempt to re-enable bridges that have already been enabled.

Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 118c77778d29..68f91a252595 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -184,8 +184,10 @@ void pci_enable_bridges(struct pci_bus *bus)
 
         list_for_each_entry(dev, &bus->devices, bus_list) {
                 if (dev->subordinate) {
-                        retval = pci_enable_device(dev);
-                        pci_set_master(dev);
+                        if (atomic_read(&dev->enable_cnt) == 0) {
+                                retval = pci_enable_device(dev);
+                                pci_set_master(dev);
+                        }
                         pci_enable_bridges(dev->subordinate);
                 }
         }