pata: expose set_mode method so it can be wrapped

This splits set_mode into do_set_mode and the wrapper so that a driver can
call the standard method inside its own.  This in theory also obsoletes
->post_set_mode().

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3451ef9..c145d9d 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -831,6 +831,7 @@
 extern int ata_scsi_change_queue_depth(struct scsi_device *sdev,
 				       int queue_depth);
 extern struct ata_device *ata_dev_pair(struct ata_device *adev);
+extern int ata_do_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev);
 extern u8 ata_irq_on(struct ata_port *ap);
 extern u8 ata_dummy_irq_on(struct ata_port *ap);
 extern u8 ata_irq_ack(struct ata_port *ap, unsigned int chk_drq);