diff -urN linux-2.6.23-rc1.orig/drivers/ata/ata_piix.c linux-2.6.23-rc1/drivers/ata/ata_piix.c
--- linux-2.6.23-rc1.orig/drivers/ata/ata_piix.c	2007-08-03 21:29:02.000000000 +0100
+++ linux-2.6.23-rc1/drivers/ata/ata_piix.c	2007-08-03 21:24:53.000000000 +0100
@@ -128,7 +128,8 @@
 	ich6_sata_ahci		= 7,
 	ich6m_sata_ahci		= 8,
 	ich8_sata_ahci		= 9,
-	piix_pata_mwdma		= 10,	/* PIIX3 MWDMA only */
+	ich8m_sata_ahci		= 10,
+	piix_pata_mwdma		= 11,	/* PIIX3 MWDMA only */
 
 	/* constants for mapping table */
 	P0			= 0,  /* port 0 */
@@ -232,7 +233,7 @@
 	/* SATA Controller 2 IDE (ICH8) */
 	{ 0x8086, 0x2825, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_ahci },
 	/* Mobile SATA Controller IDE (ICH8M) */
-	{ 0x8086, 0x2828, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_ahci },
+	{ 0x8086, 0x2828, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8m_sata_ahci },
 	/* SATA Controller IDE (ICH9) */
 	{ 0x8086, 0x2920, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_ahci },
 	/* SATA Controller IDE (ICH9) */
@@ -428,7 +429,19 @@
 		/* PM   PS   SM   SS       MAP */
 		{  P0,  P2,  P1,  P3 }, /* 00b (hardwired when in AHCI) */
 		{  RV,  RV,  RV,  RV },
-		{  IDE,  IDE,  NA,  NA }, /* 10b (IDE mode) */
+		{ IDE, IDE,  NA,  NA }, /* 10b (IDE mode) */
+		{  RV,  RV,  RV,  RV },
+	},
+};
+
+static const struct piix_map_db ich8m_map_db = {
+	.mask = 0x3,
+	.port_enable = 0x3,
+	.map = {
+		/* PM   PS   SM   SS       MAP */
+		{  P0,  P2,  P1,  P3 }, /* 00b (hardwired when in AHCI) */
+		{  RV,  RV,  RV,  RV },
+		{  P0,  P2, IDE, IDE }, /* 10b (IDE mode) */
 		{  RV,  RV,  RV,  RV },
 	},
 };
@@ -439,6 +452,7 @@
 	[ich6_sata_ahci]	= &ich6_map_db,
 	[ich6m_sata_ahci]	= &ich6m_map_db,
 	[ich8_sata_ahci]	= &ich8_map_db,
+	[ich8m_sata_ahci]	= &ich8m_map_db,
 };
 
 static struct ata_port_info piix_port_info[] = {
@@ -544,7 +558,18 @@
 		.port_ops	= &piix_sata_ops,
 	},
 
-	/* piix_pata_mwdma: 10:  PIIX3 MWDMA only */
+	/* ich8m_sata_ahci: 10 */
+	{
+		.sht		= &piix_sht,
+		.flags		= PIIX_SATA_FLAGS | PIIX_FLAG_SCR |
+				  PIIX_FLAG_AHCI,
+		.pio_mask	= 0x1f,	/* pio0-4 */
+		.mwdma_mask	= 0x07, /* mwdma0-2 */
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &piix_sata_ops,
+	},
+
+	/* piix_pata_mwdma: 11:  PIIX3 MWDMA only */
 	{
 		.sht		= &piix_sht,
 		.flags		= PIIX_PATA_FLAGS,