commit 57cd0a28095a31889e9762c25425e1cbcf27b48e
Author: Bjorn Helgaas <bhelgaas@google.com>
Date:   Wed Aug 24 13:17:07 2011 -0600

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 42bb0c9..0c007fc 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -160,6 +160,11 @@ static int __devinit piix4_setup(struct pci_dev *PIIX4_dev,
 		force = 0;
 	} else {
 		pci_read_config_word(PIIX4_dev, SMBBA, &piix4_smba);
+		if ((piix4_smba & 0x1) != 0x1) {
+			dev_err(&PIIX4_dev->dev, "MMIO SMBus base address "
+				"(%#x) not supported\n", piix4_smba);
+			return -ENODEV;
+		}
 		piix4_smba &= 0xfff0;
 		if(piix4_smba == 0) {
 			dev_err(&PIIX4_dev->dev, "SMBus base address "