ahci: Enable SB600 64bit DMA on MSI K9A2 Platinum v2

Like the Asus M2A-VM, MSI's K9A2 Platinum (MS-7376) can also support 64bit
DMA. It is a new enough board that all the BIOS releases work correctly with
64bit DMA enabled.
Signed-off-by: Mark Nelson <mdnelson8@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/ahci.c

@@ -2718,6 +2718,30 @@ static bool ahci_sb600_enable_64bit(struct pci_dev *pdev)
 			},
 			.driver_data = "20071026",	/* yyyymmdd */
 		},
+		/*
+		 * All BIOS versions for the MSI K9A2 Platinum (MS-7376)
+		 * support 64bit DMA.
+		 *
+		 * BIOS versions earlier than 1.5 had the Manufacturer DMI
+		 * fields as "MICRO-STAR INTERANTIONAL CO.,LTD".
+		 * This spelling mistake was fixed in BIOS version 1.5, so
+		 * 1.5 and later have the Manufacturer as
+		 * "MICRO-STAR INTERNATIONAL CO.,LTD".
+		 * So try to match on DMI_BOARD_VENDOR of "MICRO-STAR INTER".
+		 *
+		 * BIOS versions earlier than 1.9 had a Board Product Name
+		 * DMI field of "MS-7376". This was changed to be
+		 * "K9A2 Platinum (MS-7376)" in version 1.9, but we can still
+		 * match on DMI_BOARD_NAME of "MS-7376".
+		 */
+		{
+			.ident = "MSI K9A2 Platinum",
+			.matches = {
+				DMI_MATCH(DMI_BOARD_VENDOR,
+					  "MICRO-STAR INTER"),
+				DMI_MATCH(DMI_BOARD_NAME, "MS-7376"),
+			},
+		},
 		{ }
 	};
 	const struct dmi_system_id *match;
@@ -2729,18 +2753,24 @@ static bool ahci_sb600_enable_64bit(struct pci_dev *pdev)
 	    !match)
 		return false;
 
+	if (!match->driver_data)
+		goto enable_64bit;
+
 	dmi_get_date(DMI_BIOS_DATE, &year, &month, &date);
 	snprintf(buf, sizeof(buf), "%04d%02d%02d", year, month, date);
 
-	if (strcmp(buf, match->driver_data) >= 0) {
-		dev_printk(KERN_WARNING, &pdev->dev, "%s: enabling 64bit DMA\n",
-			   match->ident);
-		return true;
-	} else {
+	if (strcmp(buf, match->driver_data) >= 0)
+		goto enable_64bit;
+	else {
 		dev_printk(KERN_WARNING, &pdev->dev, "%s: BIOS too old, "
 			   "forcing 32bit DMA, update BIOS\n", match->ident);
 		return false;
 	}
+
+enable_64bit:
+	dev_printk(KERN_WARNING, &pdev->dev, "%s: enabling 64bit DMA\n",
+		   match->ident);
+	return true;
 }
 
 static bool ahci_broken_system_poweroff(struct pci_dev *pdev)