pata_sis: FIFO whack

If you are using a SiS controller and the BIOS didn't set it up then the
FIFO may be left active when we try and set up the CD. Not convinced this
matters but I'd prefer to be safe
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/ata/pata_sis.c

@@ -149,6 +149,9 @@ static int sis_pre_reset(struct ata_port *ap, unsigned long deadline)
 	if (!pci_test_config_bits(pdev, &sis_enable_bits[ap->port_no]))
 		return -ENOENT;
 
+	/* Clear the FIFO settings. We can't enable the FIFO until
+	   we know we are poking at a disk */
+	pci_write_config_byte(pdev, 0x4B, 0);
 	return ata_std_prereset(ap, deadline);
 }