ata_piix: improve combined mode handling

index 66b6847..22e86cb 100644
@@ -645,10 +645,14 @@ static inline unsigned int ata_tag_valid
 	return (tag < ATA_MAX_QUEUE) ? 1 : 0;
 }
 
+static inline unsigned int ata_class_present(unsigned int class)
+{
+	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI;
+}
+
 static inline unsigned int ata_dev_present(const struct ata_device *dev)
 {
-	return ((dev->class == ATA_DEV_ATA) ||
-		(dev->class == ATA_DEV_ATAPI));
+	return ata_class_present(dev->class);
 }
 
 static inline u8 ata_chk_status(struct ata_port *ap)

index c662bf5..5988d5f 100644
@@ -119,11 +119,14 @@ enum {
 	PIIX_80C_PRI		= (1 << 5) | (1 << 4),
 	PIIX_80C_SEC		= (1 << 7) | (1 << 6),
 
-	ich5_pata		= 0,
-	ich5_sata		= 1,
-	piix4_pata		= 2,
-	ich6_sata		= 3,
-	ich6_sata_ahci		= 4,
+	/* controller IDs */
+	piix4_pata		= 0,
+	ich5_pata		= 1,
+	ich5_sata		= 2,
+	esb_sata		= 3,
+	ich6_sata		= 4,
+	ich6_sata_ahci		= 5,
+	ich6m_sata_ahci		= 6,
 
 	PIIX_AHCI_DEVICE	= 6,
 };

@@ -149,19 +152,32 @@ static const struct pci_device_id piix_p
 	 * list in drivers/pci/quirks.c.
 	 */
 
+	/* 82801EB (ICH5) */
 	{ 0x8086, 0x24d1, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich5_sata },
+	/* 82801EB (ICH5) */
 	{ 0x8086, 0x24df, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich5_sata },
-	{ 0x8086, 0x25a3, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich5_sata },
-	{ 0x8086, 0x25b0, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich5_sata },
+	/* 6300ESB (ICH5 variant with broken PCS present bits) */
+	{ 0x8086, 0x25a3, PCI_ANY_ID, PCI_ANY_ID, 0, 0, esb_sata },
+	/* 6300ESB pretending RAID */
+	{ 0x8086, 0x25b0, PCI_ANY_ID, PCI_ANY_ID, 0, 0, esb_sata },
+	/* 82801FB/FW (ICH6/ICH6W) */
 	{ 0x8086, 0x2651, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata },
+	/* 82801FR/FRW (ICH6R/ICH6RW) */
 	{ 0x8086, 0x2652, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
-	{ 0x8086, 0x2653, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
+	/* 82801FBM ICH6M (ICH6R with only port 0 and 2 implemented) */
+	{ 0x8086, 0x2653, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6m_sata_ahci },
+	/* 82801GB/GR/GH (ICH7, identical to ICH6) */
 	{ 0x8086, 0x27c0, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
-	{ 0x8086, 0x27c4, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
+	/* 2801GBM/GHM (ICH7M, identical to ICH6M) */
+	{ 0x8086, 0x27c4, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6m_sata_ahci },
+	/* Enterprise Southbridge 2 (where's the datasheet?) */
 	{ 0x8086, 0x2680, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
+	/* SATA Controller 1 IDE (ICH8, no datasheet yet) */
 	{ 0x8086, 0x2820, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
+	/* SATA Controller 2 IDE (ICH8, ditto) */
 	{ 0x8086, 0x2825, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
-	{ 0x8086, 0x2828, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6_sata_ahci },
+	/* Mobile SATA Controller IDE (ICH8M, ditto) */
+	{ 0x8086, 0x2828, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich6m_sata_ahci },
 
 	{ }	/* terminate list */
 };

@@ -255,6 +271,20 @@ static const struct ata_port_operations 
 };
 
 static struct ata_port_info piix_port_info[] = {
+	/* piix4_pata */
+	{
+		.sht		= &piix_sht,
+		.host_flags	= ATA_FLAG_SLAVE_POSS,
+		.pio_mask	= 0x1f,	/* pio0-4 */
+#if 0
+		.mwdma_mask	= 0x06, /* mwdma1-2 */
+#else
+		.mwdma_mask	= 0x00, /* mwdma broken */
+#endif
+		.udma_mask	= ATA_UDMA_MASK_40C,
+		.port_ops	= &piix_pata_ops,
+	},
+
 	/* ich5_pata */
 	{
 		.sht		= &piix_sht,

@@ -280,18 +310,15 @@ static struct ata_port_info piix_port_in
 		.port_ops	= &piix_sata_ops,
 	},
 
-	/* piix4_pata */
+	/* i6300esb_sata */
 	{
 		.sht		= &piix_sht,
-		.host_flags	= ATA_FLAG_SLAVE_POSS,
+		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED |
+				  PIIX_FLAG_CHECKINTR,
 		.pio_mask	= 0x1f,	/* pio0-4 */
-#if 0
-		.mwdma_mask	= 0x06, /* mwdma1-2 */
-#else
-		.mwdma_mask	= 0x00, /* mwdma broken */
-#endif
-		.udma_mask	= ATA_UDMA_MASK_40C,
-		.port_ops	= &piix_pata_ops,
+		.mwdma_mask	= 0x07, /* mwdma0-2 */
+		.udma_mask	= 0x7f,	/* udma0-6 */
+		.port_ops	= &piix_sata_ops,
 	},
 
 	/* ich6_sata */

@@ -316,6 +343,18 @@ static struct ata_port_info piix_port_in
 		.udma_mask	= 0x7f,	/* udma0-6 */
 		.port_ops	= &piix_sata_ops,
 	},
+
+	/* ich6m_sata_ahci */
+	{
+		.sht		= &piix_sht,
+		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
+				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
+				  PIIX_FLAG_AHCI,
+		.pio_mask	= 0x1f,	/* pio0-4 */
+		.mwdma_mask	= 0x07, /* mwdma0-2 */
+		.udma_mask	= 0x7f,	/* udma0-6 */
+		.port_ops	= &piix_sata_ops,
+	},
 };
 
 static struct pci_bits piix_enable_bits[] = {

index 5988d5f..987a7cc 100644
@@ -101,6 +101,8 @@ enum {
 	ICH5_PCS		= 0x92,	/* port control and status */
 	PIIX_SCC		= 0x0A, /* sub-class code register */
 
+	PIIX_FLAG_IGN_PRESENT	= (1 << 25), /* ignore PCS present bits */
+	PIIX_FLAG_SCR		= (1 << 26), /* SCR available */
 	PIIX_FLAG_AHCI		= (1 << 27), /* AHCI possible */
 	PIIX_FLAG_CHECKINTR	= (1 << 28), /* make sure PCI INTx enabled */
 	PIIX_FLAG_COMBINED	= (1 << 29), /* combined mode possible */

@@ -314,7 +316,7 @@ static struct ata_port_info piix_port_in
 	{
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED |
-				  PIIX_FLAG_CHECKINTR,
+				  PIIX_FLAG_CHECKINTR | PIIX_FLAG_IGN_PRESENT,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */

@@ -325,7 +327,8 @@ static struct ata_port_info piix_port_in
 	{
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
-				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS,
+				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
+				  PIIX_FLAG_SCR,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */

@@ -337,7 +340,7 @@ static struct ata_port_info piix_port_in
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
 				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
-				  PIIX_FLAG_AHCI,
+				  PIIX_FLAG_SCR | PIIX_FLAG_AHCI,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */

@@ -349,7 +352,7 @@ static struct ata_port_info piix_port_in
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
 				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
-				  PIIX_FLAG_AHCI,
+				  PIIX_FLAG_SCR | PIIX_FLAG_AHCI,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */

index 72e38e6..9327b62 100644
@@ -101,7 +101,7 @@ enum {
 	ICH5_PCS		= 0x92,	/* port control and status */
 	PIIX_SCC		= 0x0A, /* sub-class code register */
 
-	PIIX_FLAG_IGN_PRESENT	= (1 << 25), /* ignore PCS present bits */
+	PIIX_FLAG_IGNORE_PCS	= (1 << 25), /* ignore PCS present bits */
 	PIIX_FLAG_SCR		= (1 << 26), /* SCR available */
 	PIIX_FLAG_AHCI		= (1 << 27), /* AHCI possible */
 	PIIX_FLAG_CHECKINTR	= (1 << 28), /* make sure PCI INTx enabled */

@@ -365,7 +365,7 @@ static struct ata_port_info piix_port_in
 	{
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED |
-				  PIIX_FLAG_CHECKINTR | PIIX_FLAG_IGN_PRESENT,
+				  PIIX_FLAG_CHECKINTR | PIIX_FLAG_IGNORE_PCS,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */

@@ -538,7 +538,7 @@ static unsigned int piix_sata_probe (str
 		port = map[base + i];
 		if (port < 0)
 			continue;
-		if (ap->flags & PIIX_FLAG_IGN_PRESENT || pcs & 1 << (4 + port))
+		if (ap->flags & PIIX_FLAG_IGNORE_PCS || pcs & 1 << (4 + port))
 			present_mask |= 1 << i;
 		else
 			pcs &= ~(1 << port);

index 987a7cc..4080b8b 100644
@@ -112,9 +112,6 @@ enum {
 	/* combined mode.  if set, PATA is channel 0.
 	 * if clear, PATA is channel 1.
 	 */
-	PIIX_COMB_PATA_P0	= (1 << 1),
-	PIIX_COMB		= (1 << 2), /* combined mode enabled? */
-
 	PIIX_PORT_ENABLED	= (1 << 0),
 	PIIX_PORT_PRESENT	= (1 << 4),
 

@@ -130,9 +127,23 @@ enum {
 	ich6_sata_ahci		= 5,
 	ich6m_sata_ahci		= 6,
 
+	/* constants for mapping table */
+	P0			= 0,  /* port 0 */
+	P1			= 1,  /* port 1 */
+	P2			= 2,  /* port 2 */
+	P3			= 3,  /* port 3 */
+	IDE			= -1, /* IDE */
+	NA			= -2, /* not avaliable */
+	RV			= -3, /* reserved */
+
 	PIIX_AHCI_DEVICE	= 6,
 };
 
+struct piix_map_db {
+	const u32 mask;
+	const int map[][4];
+};
+
 static int piix_init_one (struct pci_dev *pdev,
 				    const struct pci_device_id *ent);
 

@@ -272,6 +283,43 @@ static const struct ata_port_operations 
 	.host_stop		= ata_host_stop,
 };
 
+static struct piix_map_db ich5_map_db = {
+	.mask = 0x7,
+	.map = {
+		/* PM   PS   SM   SS       MAP  */
+		{  P0,  NA,  P1,  NA }, /* 000b */
+		{  P1,  NA,  P0,  NA }, /* 001b */
+		{  RV,  RV,  RV,  RV },
+		{  RV,  RV,  RV,  RV },
+		{  P0,  P1, IDE, IDE }, /* 100b */
+		{  P1,  P0, IDE, IDE }, /* 101b */
+		{ IDE, IDE,  P0,  P1 }, /* 110b */
+		{ IDE, IDE,  P1,  P0 }, /* 111b */
+	},
+};
+
+static struct piix_map_db ich6_map_db = {
+	.mask = 0x3,
+	.map = {
+		/* PM   PS   SM   SS       MAP */
+		{  P0,  P1,  P2,  P3 }, /* 00b */
+		{ IDE, IDE,  P1,  P3 }, /* 01b */
+		{  P0,  P2, IDE, IDE }, /* 10b */
+		{  RV,  RV,  RV,  RV },
+	},
+};
+
+static struct piix_map_db ich6m_map_db = {
+	.mask = 0x3,
+	.map = {
+		/* PM   PS   SM   SS       MAP */
+		{  P0,  P1,  P2,  P3 }, /* 00b */
+		{  RV,  RV,  RV,  RV },
+		{  P0,  P2, IDE, IDE }, /* 10b */
+		{  RV,  RV,  RV,  RV },
+	},
+};
+
 static struct ata_port_info piix_port_info[] = {
 	/* piix4_pata */
 	{

@@ -310,6 +358,7 @@ static struct ata_port_info piix_port_in
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */
 		.port_ops	= &piix_sata_ops,
+		.private_data	= &ich5_map_db,
 	},
 
 	/* i6300esb_sata */

@@ -321,42 +370,45 @@ static struct ata_port_info piix_port_in
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */
 		.port_ops	= &piix_sata_ops,
+		.private_data	= &ich5_map_db,
 	},
 
 	/* ich6_sata */
 	{
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
-				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
-				  PIIX_FLAG_SCR,
+				  PIIX_FLAG_CHECKINTR | PIIX_FLAG_SCR,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */
 		.port_ops	= &piix_sata_ops,
+		.private_data	= &ich6_map_db,
 	},
 
 	/* ich6_sata_ahci */
 	{
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
-				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
-				  PIIX_FLAG_SCR | PIIX_FLAG_AHCI,
+				  PIIX_FLAG_CHECKINTR | PIIX_FLAG_SCR |
+				  PIIX_FLAG_AHCI,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */
 		.port_ops	= &piix_sata_ops,
+		.private_data	= &ich6_map_db,
 	},
 
 	/* ich6m_sata_ahci */
 	{
 		.sht		= &piix_sht,
 		.host_flags	= ATA_FLAG_SATA | PIIX_FLAG_COMBINED_ICH6 |
-				  PIIX_FLAG_CHECKINTR | ATA_FLAG_SLAVE_POSS |
-				  PIIX_FLAG_SCR | PIIX_FLAG_AHCI,
+				  PIIX_FLAG_CHECKINTR | PIIX_FLAG_SCR |
+				  PIIX_FLAG_AHCI,
 		.pio_mask	= 0x1f,	/* pio0-4 */
 		.mwdma_mask	= 0x07, /* mwdma0-2 */
 		.udma_mask	= 0x7f,	/* udma0-6 */
 		.port_ops	= &piix_sata_ops,
+		.private_data	= &ich6m_map_db,
 	},
 };
 

@@ -708,6 +760,54 @@ static int __devinit piix_check_450nx_er
 	return no_piix_dma;
 }		
 
+static void __devinit piix_init_sata_map(struct pci_dev *pdev,
+					 struct ata_port_info *pinfo)
+{
+	struct piix_map_db *map_db = pinfo[0].private_data;
+	const unsigned int *map;
+	int i, invalid_map = 0;
+	u8 map_value;
+
+	pci_read_config_byte(pdev, ICH5_PMR, &map_value);
+
+	map = map_db->map[map_value & map_db->mask];
+
+	dev_printk(KERN_INFO, &pdev->dev, "MAP [");
+	for (i = 0; i < 4; i++) {
+		switch (map[i]) {
+		case RV:
+			invalid_map = 1;
+			printk(" XX");
+			break;
+
+		case NA:
+			printk(" --");
+			break;
+
+		case IDE:
+			WARN_ON((i & 1) || map[i + 1] != IDE);
+			pinfo[i / 2] = piix_port_info[ich5_pata];
+			i++;
+			printk(" IDE IDE");
+			break;
+
+		default:
+			printk(" P%d", map[i]);
+			if (i & 1)
+				pinfo[i / 2].host_flags |= ATA_FLAG_SLAVE_POSS;
+			break;
+		}
+	}
+	printk(" ]\n");
+
+	if (invalid_map)
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "invalid MAP value %u\n", map_value);
+
+	pinfo[0].private_data = (void *)map;
+	pinfo[1].private_data = (void *)map;
+}
+
 /**
  *	piix_init_one - Register PIIX ATA PCI device with kernel services
  *	@pdev: PCI device to register

@@ -726,9 +826,8 @@ static int __devinit piix_check_450nx_er
 static int piix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	static int printed_version;
-	struct ata_port_info *port_info[2];
-	unsigned int combined = 0;
-	unsigned int pata_chan = 0, sata_chan = 0;
+	struct ata_port_info port_info[2];
+	struct ata_port_info *ppinfo[2] = { &port_info[0], &port_info[1] };
 	unsigned long host_flags;
 
 	if (!printed_version++)

@@ -739,10 +838,10 @@ static int piix_init_one (struct pci_dev
 	if (!in_module_init)
 		return -ENODEV;
 
-	port_info[0] = &piix_port_info[ent->driver_data];
-	port_info[1] = &piix_port_info[ent->driver_data];
+	port_info[0] = piix_port_info[ent->driver_data];
+	port_info[1] = piix_port_info[ent->driver_data];
 
-	host_flags = port_info[0]->host_flags;
+	host_flags = port_info[0].host_flags;
 
 	if (host_flags & PIIX_FLAG_AHCI) {
 		u8 tmp;

@@ -754,37 +853,9 @@ static int piix_init_one (struct pci_dev
 		}
 	}
 
-	if (host_flags & PIIX_FLAG_COMBINED) {
-		u8 tmp;
-		pci_read_config_byte(pdev, ICH5_PMR, &tmp);
-
-		if (host_flags & PIIX_FLAG_COMBINED_ICH6) {
-			switch (tmp & 0x3) {
-			case 0:
-				break;
-			case 1:
-				combined = 1;
-				sata_chan = 1;
-				break;
-			case 2:
-				combined = 1;
-				pata_chan = 1;
-				break;
-			case 3:
-				dev_printk(KERN_WARNING, &pdev->dev,
-					   "invalid MAP value %u\n", tmp);
-				break;
-			}
-		} else {
-			if (tmp & PIIX_COMB) {
-				combined = 1;
-				if (tmp & PIIX_COMB_PATA_P0)
-					sata_chan = 1;
-				else
-					pata_chan = 1;
-			}
-		}
-	}
+	/* Initialize SATA map */
+	if (host_flags & ATA_FLAG_SATA)
+		piix_init_sata_map(pdev, port_info);
 
 	/* On ICH5, some BIOSen disable the interrupt using the
 	 * PCI_COMMAND_INTX_DISABLE bit added in PCI 2.3.

@@ -795,25 +866,16 @@ static int piix_init_one (struct pci_dev
 	if (host_flags & PIIX_FLAG_CHECKINTR)
 		pci_intx(pdev, 1);
 
-	if (combined) {
-		port_info[sata_chan] = &piix_port_info[ent->driver_data];
-		port_info[sata_chan]->host_flags |= ATA_FLAG_SLAVE_POSS;
-		port_info[pata_chan] = &piix_port_info[ich5_pata];
-
-		dev_printk(KERN_WARNING, &pdev->dev,
-			   "combined mode detected (p=%u, s=%u)\n",
-			   pata_chan, sata_chan);
-	}
 	if (piix_check_450nx_errata(pdev)) {
 		/* This writes into the master table but it does not
 		   really matter for this errata as we will apply it to
 		   all the PIIX devices on the board */
-		port_info[0]->mwdma_mask = 0;
-		port_info[0]->udma_mask = 0;
-		port_info[1]->mwdma_mask = 0;
-		port_info[1]->udma_mask = 0;
+		port_info[0].mwdma_mask = 0;
+		port_info[0].udma_mask = 0;
+		port_info[1].mwdma_mask = 0;
+		port_info[1].udma_mask = 0;
 	}
-	return ata_pci_init_one(pdev, port_info, 2);
+	return ata_pci_init_one(pdev, ppinfo, 2);
 }
 
 static int __init piix_init(void)

index 4080b8b..72e38e6 100644
@@ -499,44 +499,59 @@ static int piix_pata_probe_reset(struct 
  *	piix_sata_probe - Probe PCI device for present SATA devices
  *	@ap: Port associated with the PCI device we wish to probe
  *
- *	Reads SATA PCI device's PCI config register Port Configuration
- *	and Status (PCS) to determine port and device availability.
+ *	Reads and configures SATA PCI device's PCI config register
+ *	Port Configuration and Status (PCS) to determine port and
+ *	device availability.
  *
  *	LOCKING:
  *	None (inherited from caller).
  *
  *	RETURNS:
- *	Non-zero if port is enabled, it may or may not have a device
- *	attached in that case (PRESENT bit would only be set if BIOS probe
- *	was done). Zero is returned if port is disabled.
+ *	Mask of avaliable devices on the port.
  */
-static int piix_sata_probe (struct ata_port *ap)
+static unsigned int piix_sata_probe (struct ata_port *ap)
 {
 	struct pci_dev *pdev = to_pci_dev(ap->host_set->dev);
-	int combined = (ap->flags & ATA_FLAG_SLAVE_POSS);
-	int orig_mask, mask, i;
+	const unsigned int *map = ap->host_set->private_data;
+	int base = 2 * ap->hard_port_no;
+	unsigned int present_mask = 0;
+	int port, i;
 	u8 pcs;
 
 	pci_read_config_byte(pdev, ICH5_PCS, &pcs);
-	orig_mask = (int) pcs & 0xff;
+	DPRINTK("ata%u: ENTER, pcs=0x%x base=%d\n", ap->id, pcs, base);
 
-	/* TODO: this is vaguely wrong for ICH6 combined mode,
-	 * where only two of the four SATA ports are mapped
-	 * onto a single ATA channel.  It is also vaguely inaccurate
-	 * for ICH5, which has only two ports.  However, this is ok,
-	 * as further device presence detection code will handle
-	 * any false positives produced here.
-	 */
+	/* enable all ports on this ap and wait for them to settle */
+	for (i = 0; i < 2; i++) {
+		port = map[base + i];
+		if (port >= 0)
+			pcs |= 1 << port;
+	}
 
-	for (i = 0; i < 4; i++) {
-		mask = (PIIX_PORT_ENABLED << i);
+	pci_write_config_byte(pdev, ICH5_PCS, pcs);
+	msleep(100);
+
+	/* let's see which devices are present */
+	pci_read_config_byte(pdev, ICH5_PCS, &pcs);
 
-		if ((orig_mask & mask) == mask)
-			if (combined || (i == ap->hard_port_no))
-				return 1;
+	for (i = 0; i < 2; i++) {
+		port = map[base + i];
+		if (port < 0)
+			continue;
+		if (ap->flags & PIIX_FLAG_IGN_PRESENT || pcs & 1 << (4 + port))
+			present_mask |= 1 << i;
+		else
+			pcs &= ~(1 << port);
 	}
 
-	return 0;
+	/* disable offline ports on non-AHCI controllers */
+	if (!(ap->flags & PIIX_FLAG_AHCI))
+		pci_write_config_byte(pdev, ICH5_PCS, pcs);
+
+	DPRINTK("ata%u: LEAVE, pcs=0x%x present_mask=0x%x\n",
+		ap->id, pcs, present_mask);
+
+	return present_mask;
 }
 
 /**

index 72e38e6..625db11 100644
@@ -566,14 +566,31 @@ static unsigned int piix_sata_probe (str
  */
 static int piix_sata_probe_reset(struct ata_port *ap, unsigned int *classes)
 {
-	if (!piix_sata_probe(ap)) {
+	unsigned int mask;
+	int i, rc;
+
+	mask = piix_sata_probe(ap);
+	if (!mask) {
 		printk(KERN_INFO "ata%u: SATA port has no device.\n", ap->id);
 		return 0;
 	}
 
-	return ata_drive_probe_reset(ap, ata_std_probeinit,
-				     ata_std_softreset, NULL,
-				     ata_std_postreset, classes);
+	rc = ata_drive_probe_reset(ap, ata_std_probeinit,
+				   ata_std_softreset, NULL,
+				   ata_std_postreset, classes);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < 2; i++) {
+		if (ata_class_present(classes[i]) && !(mask & (1 << i))) {
+			printk(KERN_WARNING "ata%u: dev %u class %d for "
+			       "non-existent device, fixing up\n",
+			       ap->id, i, classes[i]);
+			classes[i] = ATA_DEV_NONE;
+		}
+	}
+
+	return 0;
 }
 
 /**