[PATCH] PCI domain scanning fix

From: Matthew Wilcox <willy@debian.org>

ppc64 oopses on boot because pci_scan_bus_parented() is unexpectedly
returning NULL.  Change pci_scan_bus_parented() to correctly handle
overlapping PCI bus numbers on different domains.

drivers/pci/probe.c

@@ -637,12 +637,6 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent, int bus,
 {
 	struct pci_bus *b;
 
-	if (pci_find_bus(0, bus)) {
-		/* If we already got to this bus through a different bridge, ignore it */
-		DBG("PCI: Bus %02x already known\n", bus);
-		return NULL;
-	}
-
 	b = pci_alloc_bus();
 	if (!b)
 		return NULL;
@@ -656,6 +650,14 @@ struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent, int bus,
 	b->sysdata = sysdata;
 	b->ops = ops;
 
+	if (pci_find_bus(pci_domain_nr(b), bus)) {
+		/* If we already got to this bus through a different bridge, ignore it */
+		DBG("PCI: Bus %02x already known\n", bus);
+		kfree(b->dev);
+		kfree(b);
+		return NULL;
+	}
+
 	list_add_tail(&b->node, &pci_root_buses);
 
 	memset(b->dev,0,sizeof(*(b->dev)));