PCI: check if bus has a proper bridge device before triggering SBR

For devices attached to the root bus, we can't trigger Secondary Bus
Reset because there is no bridge device associated with the bus. So
need to check bus->self again NULL first before using it.

Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6c93af5..d5d6f56 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2171,7 +2171,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
        u16 ctrl;
        struct pci_dev *pdev;
 
-       if (dev->subordinate)
+       if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
                return -ENOTTY;
 
        list_for_each_entry(pdev, &dev->bus->devices, bus_list)