-** used by drivers/pci/pci.c:pci_do_scan_bus()
-** 0 == check if bridge is numbered before re-numbering.
-** 1 == pci_do_scan_bus() should automatically number all PCI-PCI bridges.
-**
-** REVISIT:
-** To date, only alpha sets this to one. We'll need to set this
-** to zero for legacy platforms and one for PAT platforms.
-*/
-#define pcibios_assign_all_busses() (pdc_type == PDC_TYPE_PAT)
-#define pcibios_scan_all_fns(a, b) 0
+ * pcibios_assign_all_busses() is used in drivers/pci/pci.c:pci_do_scan_bus()
+ * 0 == check if bridge is numbered before re-numbering.
+ * 1 == pci_do_scan_bus() should automatically number all PCI-PCI bridges.
+ *
+ * We *should* set this to zero for "legacy" platforms and one
+ * for PAT platforms.
+ *
+ * But legacy platforms also need to renumber the busses below a Host
+ * Bus controller. Adding a 4-port Tulip card on the first PCI root
+ * bus of a C200 resulted in the secondary bus being numbered as 1.
+ * The second PCI host bus controller's root bus had already been
+ * assigned bus number 1 by firmware and sysfs complained.
+ *
+ * Firmware isn't doing anything wrong here since each controller
+ * is its own PCI domain. It's simpler and easier for us to renumber
+ * the busses rather than treat each Dino as a separate PCI domain.
+ * Eventually, we may want to introduce PCI domains for Superdome or
+ * rp7420/8420 boxes and then revisit this issue.
+ */
+#define pcibios_assign_all_busses() (1)
+#define pcibios_scan_all_fns(a, b) (0)