ahci: disable NCQ on Samsung pci-e SSDs on macbooks

commit 67809f85 upstream.

Samsung's pci-e SSDs with device ID 0x1600 which are found on some
macbooks time out on NCQ commands.  Blacklist NCQ on the device so
that the affected machines can at least boot.
Original-patch-by: Levente Kurusa <levex@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=60731
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/ata/ahci.c

@@ -61,6 +61,7 @@ enum board_ids {
 	/* board IDs by feature in alphabetical order */
 	board_ahci,
 	board_ahci_ign_iferr,
+	board_ahci_noncq,
 	board_ahci_nosntf,
 	board_ahci_yes_fbs,
 
@@ -123,6 +124,13 @@ static const struct ata_port_info ahci_port_info[] = {
 		.udma_mask	= ATA_UDMA6,
 		.port_ops	= &ahci_ops,
 	},
+	[board_ahci_noncq] = {
+		AHCI_HFLAGS	(AHCI_HFLAG_NO_NCQ),
+		.flags		= AHCI_FLAG_COMMON,
+		.pio_mask	= ATA_PIO4,
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &ahci_ops,
+	},
 	[board_ahci_nosntf] =
 	{
 		AHCI_HFLAGS	(AHCI_HFLAG_NO_SNTF),
@@ -458,6 +466,12 @@ static const struct pci_device_id ahci_pci_tbl[] = {
 	{ PCI_VDEVICE(ASMEDIA, 0x0611), board_ahci },	/* ASM1061 */
 	{ PCI_VDEVICE(ASMEDIA, 0x0612), board_ahci },	/* ASM1062 */
 
+	/*
+	 * Samsung SSDs found on some macbooks.  NCQ times out.
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=60731
+	 */
+	{ PCI_VDEVICE(SAMSUNG, 0x1600), board_ahci_noncq },
+
 	/* Enmotus */
 	{ PCI_DEVICE(0x1c44, 0x8000), board_ahci },