diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index edb37f3d558d7c99194ba2f0cd72d5b63d553851..236d8fd4e72bbc44a86d672735eeabe8424f7af1 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -539,13 +539,19 @@ static ide_pci_device_t piix_pci_info[] __devinitdata = {
 	/*  0 */ DECLARE_PIIX_DEV("PIIXa"),
 	/*  1 */ DECLARE_PIIX_DEV("PIIXb"),
 
-	{	/* 2 */
+	/*  2 */
+	{	/*
+		 * MPIIX actually has only a single IDE channel mapped to
+		 * the primary or secondary ports depending on the value
+		 * of the bit 14 of the IDETIM register at offset 0x6c
+		 */
 		.name		= "MPIIX",
 		.init_hwif	= init_hwif_piix,
 		.channels	= 2,
 		.autodma	= NODMA,
-		.enablebits	= {{0x6D,0x80,0x80}, {0x6F,0x80,0x80}},
+		.enablebits	= {{0x6d,0xc0,0x80}, {0x6d,0xc0,0xc0}},
 		.bootable	= ON_BOARD,
+		.flags		= IDEPCI_FLAG_ISA_PORTS
 	},
 
 	/*  3 */ DECLARE_PIIX_DEV("PIIX3"),