ahci_platform: add STRICT_AHCI platform type

Some platforms need to make use of the AHCI_HFLAG_DELAY_ENGINE flag.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: stable@kernel.org
diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 48be4e1..0c86c77 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -26,6 +26,7 @@
 enum ahci_type {
 	AHCI,		/* standard platform ahci */
 	IMX53_AHCI,	/* ahci on i.mx53 */
+	STRICT_AHCI,	/* delayed DMA engine start */
 };
 
 static struct platform_device_id ahci_devtype[] = {
@@ -36,6 +37,9 @@
 		.name = "imx53-ahci",
 		.driver_data = IMX53_AHCI,
 	}, {
+		.name = "strict-ahci",
+		.driver_data = STRICT_AHCI,
+	}, {
 		/* sentinel */
 	}
 };
@@ -56,6 +60,13 @@
 		.udma_mask	= ATA_UDMA6,
 		.port_ops	= &ahci_pmp_retry_srst_ops,
 	},
+	[STRICT_AHCI] = {
+		AHCI_HFLAGS	(AHCI_HFLAG_DELAY_ENGINE),
+		.flags		= AHCI_FLAG_COMMON,
+		.pio_mask	= ATA_PIO4,
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &ahci_ops,
+	},
 };
 
 static struct scsi_host_template ahci_platform_sht = {