diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 219a4106480a..80350299a6ea 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -665,21 +665,23 @@ static void pci_bridge_check_ranges(struct pci_bus *bus)
 
 	pci_read_config_word(bridge, PCI_IO_BASE, &io);
 	if (!io) {
-		pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0);
+		pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
 		pci_read_config_word(bridge, PCI_IO_BASE, &io);
 		pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
 	}
 	if (io)
 		b_res[0].flags |= IORESOURCE_IO;
+
 	/*  DECchip 21050 pass 2 errata: the bridge may miss an address
 	    disconnect boundary by one PCI data phase.
 	    Workaround: do not use prefetching on this device. */
 	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
 		return;
+
 	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
 	if (!pmem) {
 		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
-					       0xfff0fff0);
+					       0xffe0fff0);
 		pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
 		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
 	}