sata_via: apply magic FIFO fix to vt6420 too

vt6420 has the same FIFO overflow problem as vt6421 when combined with
certain devices.  This patch applies the magic fix to vt6420 too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Martin Qvist <q@maq.dk>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/sata_via.c b/drivers/ata/sata_via.c
index c215899..8b677bb 100644
--- a/drivers/ata/sata_via.c
+++ b/drivers/ata/sata_via.c
@@ -538,7 +538,7 @@
 	return 0;
 }
 
-static void svia_configure(struct pci_dev *pdev)
+static void svia_configure(struct pci_dev *pdev, int board_id)
 {
 	u8 tmp8;
 
@@ -577,7 +577,7 @@
 	}
 
 	/*
-	 * vt6421 has problems talking to some drives.  The following
+	 * vt6420/1 has problems talking to some drives.  The following
 	 * is the fix from Joseph Chan <JosephChan@via.com.tw>.
 	 *
 	 * When host issues HOLD, device may send up to 20DW of data
@@ -596,8 +596,9 @@
 	 *
 	 * https://bugzilla.kernel.org/show_bug.cgi?id=15173
 	 * http://article.gmane.org/gmane.linux.ide/46352
+	 * http://thread.gmane.org/gmane.linux.kernel/1062139
 	 */
-	if (pdev->device == 0x3249) {
+	if (board_id == vt6420 || board_id == vt6421) {
 		pci_read_config_byte(pdev, 0x52, &tmp8);
 		tmp8 |= 1 << 2;
 		pci_write_config_byte(pdev, 0x52, tmp8);
@@ -652,7 +653,7 @@
 	if (rc)
 		return rc;
 
-	svia_configure(pdev);
+	svia_configure(pdev, board_id);
 
 	pci_set_master(pdev);
 	return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,