ata_piix: make DVD Drive recognisable on systems with Intel Sandybridge chipsets(v2)

This quirk patch fixes one kind of bug inside some Intel Sandybridge
chipsets, see reports from

       https://bugzilla.kernel.org/show_bug.cgi?id=40592.

Many guys also have reported the problem before:

	https://bugs.launchpad.net/bugs/737388
	https://bugs.launchpad.net/bugs/794642
	https://bugs.launchpad.net/bugs/782389
	......

With help from Tejun, the problem is found to be caused by 32bit PIO
mode, so introduce the quirk patch to disable 32bit PIO on SATA piix
for some Sandybridge CPT chipsets.

Seth also tested the patch on all five affected chipsets
(pci device ID: 0x1c00, 0x1c01, 0x1d00, 0x1e00, 0x1e01), and found
the patch does fix the problem.
Tested-by: Heasley, Seth <seth.heasley@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: stable@kernel.org

drivers/ata/ata_piix.c

@@ -113,6 +113,8 @@ enum {
 	PIIX_PATA_FLAGS		= ATA_FLAG_SLAVE_POSS,
 	PIIX_SATA_FLAGS		= ATA_FLAG_SATA | PIIX_FLAG_CHECKINTR,
 
+	PIIX_FLAG_PIO16		= (1 << 30), /*support 16bit PIO only*/
+
 	PIIX_80C_PRI		= (1 << 5) | (1 << 4),
 	PIIX_80C_SEC		= (1 << 7) | (1 << 6),
 
@@ -147,6 +149,7 @@ enum piix_controller_ids {
 	ich8m_apple_sata,	/* locks up on second port enable */
 	tolapai_sata,
 	piix_pata_vmw,			/* PIIX4 for VMware, spurious DMA_ERR */
+	ich8_sata_snb,
 };
 
 struct piix_map_db {
@@ -177,6 +180,7 @@ static int piix_sidpr_scr_write(struct ata_link *link,
 static int piix_sidpr_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
 			      unsigned hints);
 static bool piix_irq_check(struct ata_port *ap);
+static int piix_port_start(struct ata_port *ap);
 #ifdef CONFIG_PM
 static int piix_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
 static int piix_pci_device_resume(struct pci_dev *pdev);
@@ -298,21 +302,21 @@ static const struct pci_device_id piix_pci_tbl[] = {
 	/* SATA Controller IDE (PCH) */
 	{ 0x8086, 0x3b2e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
 	/* SATA Controller IDE (CPT) */
-	{ 0x8086, 0x1c00, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
+	{ 0x8086, 0x1c00, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_snb },
 	/* SATA Controller IDE (CPT) */
-	{ 0x8086, 0x1c01, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
+	{ 0x8086, 0x1c01, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_snb },
 	/* SATA Controller IDE (CPT) */
 	{ 0x8086, 0x1c08, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
 	/* SATA Controller IDE (CPT) */
 	{ 0x8086, 0x1c09, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
 	/* SATA Controller IDE (PBG) */
-	{ 0x8086, 0x1d00, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
+	{ 0x8086, 0x1d00, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_snb },
 	/* SATA Controller IDE (PBG) */
 	{ 0x8086, 0x1d08, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
 	/* SATA Controller IDE (Panther Point) */
-	{ 0x8086, 0x1e00, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
+	{ 0x8086, 0x1e00, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_snb },
 	/* SATA Controller IDE (Panther Point) */
-	{ 0x8086, 0x1e01, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata },
+	{ 0x8086, 0x1e01, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_sata_snb },
 	/* SATA Controller IDE (Panther Point) */
 	{ 0x8086, 0x1e08, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich8_2port_sata },
 	/* SATA Controller IDE (Panther Point) */
@@ -338,6 +342,7 @@ static struct scsi_host_template piix_sht = {
 static struct ata_port_operations piix_sata_ops = {
 	.inherits		= &ata_bmdma32_port_ops,
 	.sff_irq_check		= piix_irq_check,
+	.port_start		= piix_port_start,
 };
 
 static struct ata_port_operations piix_pata_ops = {
@@ -478,6 +483,7 @@ static const struct piix_map_db *piix_map_db_table[] = {
 	[ich8_2port_sata]	= &ich8_2port_map_db,
 	[ich8m_apple_sata]	= &ich8m_apple_map_db,
 	[tolapai_sata]		= &tolapai_map_db,
+	[ich8_sata_snb]		= &ich8_map_db,
 };
 
 static struct ata_port_info piix_port_info[] = {
@@ -606,6 +612,19 @@ static struct ata_port_info piix_port_info[] = {
 		.port_ops	= &piix_vmw_ops,
 	},
 
+	/*
+	 * some Sandybridge chipsets have broken 32 mode up to now,
+	 * see https://bugzilla.kernel.org/show_bug.cgi?id=40592
+	 */
+	[ich8_sata_snb] =
+	{
+		.flags		= PIIX_SATA_FLAGS | PIIX_FLAG_SIDPR | PIIX_FLAG_PIO16,
+		.pio_mask	= ATA_PIO4,
+		.mwdma_mask	= ATA_MWDMA2,
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &piix_sata_ops,
+	},
+
 };
 
 static struct pci_bits piix_enable_bits[] = {
@@ -649,6 +668,14 @@ static const struct ich_laptop ich_laptop[] = {
 	{ 0, }
 };
 
+static int piix_port_start(struct ata_port *ap)
+{
+	if (!(ap->flags & PIIX_FLAG_PIO16))
+		ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
+
+	return ata_bmdma_port_start(ap);
+}
+
 /**
  *	ich_pata_cable_detect - Probe host controller cable detect info
  *	@ap: Port for which cable detect info is desired