Merge tag 'pci-v4.5-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fix from Bjorn Helgaas:
 "Here's another fix for v4.5.  It fixes an ARM regression in v4.0 that
  causes many boxes to crash on boot, including cns3xxx, dove,
  footbridge, iopl13xx, ip32x, iop33x, ixp4xx, ks8695, mv78xx0, orion5x,
  pxa, sa1100, etc.

  The change is in code that's only built for ARM and ARM64.

  Summary:

  Enumeration:
    Allow generic PCI domains without bridge "parent" pointer (Krzysztof Hałasa)"

* tag 'pci-v4.5-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Allow a NULL "parent" pointer in pci_bus_assign_domain_nr()

drivers/pci/pci.c

@@ -4772,8 +4772,10 @@ int pci_get_new_domain_nr(void)
 void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
 {
 	static int use_dt_domains = -1;
-	int domain = of_get_pci_domain_nr(parent->of_node);
+	int domain = -1;
 
+	if (parent)
+		domain = of_get_pci_domain_nr(parent->of_node);
 	/*
 	 * Check DT domain and use_dt_domains values.
 	 *