diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
index 44155c5e85d1..2c4f585510c9 100644
--- a/arch/i386/pci/mmconfig.c
+++ b/arch/i386/pci/mmconfig.c
@@ -198,7 +198,9 @@ void __init pci_mmcfg_init(int type)
 	    (pci_mmcfg_config[0].base_address == 0))
 		return;
 
-	if (!e820_all_mapped(pci_mmcfg_config[0].base_address,
+	/* Only do this check when type 1 works. If it doesn't work
+	   assume we run on a Mac and always use MCFG */
+	if (type == 1 && !e820_all_mapped(pci_mmcfg_config[0].base_address,
 			pci_mmcfg_config[0].base_address + MMCONFIG_APER_MIN,
 			E820_RESERVED)) {
 		printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %x is not E820-reserved\n",
diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c
index d6b90d08476b..8bea51030d66 100644
--- a/arch/x86_64/pci/mmconfig.c
+++ b/arch/x86_64/pci/mmconfig.c
@@ -176,7 +176,9 @@ void __init pci_mmcfg_init(int type)
 	    (pci_mmcfg_config[0].base_address == 0))
 		return;
 
-	if (!e820_all_mapped(pci_mmcfg_config[0].base_address,
+	/* Only do this check when type 1 works. If it doesn't work
+           assume we run on a Mac and always use MCFG */
+	if (type == 1 && !e820_all_mapped(pci_mmcfg_config[0].base_address,
 			pci_mmcfg_config[0].base_address + MMCONFIG_APER_MIN,
 			E820_RESERVED)) {
 		printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %x is not E820-reserved\n",