libata: update libata core layer to use devres

Update libata core layer to use devres.

* ata_device_add() acquires all resources in managed mode.

* ata_host is allocated as devres associated with ata_host_release.

* Port attached status is handled as devres associated with
  ata_host_attach_release().

* Initialization failure and host removal is handedl by releasing
  devres group.

* Except for ata_scsi_release() removal, LLD interface remains the
  same.  Some functions use hacky is_managed test to support both
  managed and unmanaged devices.  These will go away once all LLDs are
  updated to use devres.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index cc229e31432f..0009818a4306 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3305,7 +3305,8 @@ EXPORT_SYMBOL_GPL(ata_sas_port_init);
 
 void ata_sas_port_destroy(struct ata_port *ap)
 {
-        ap->ops->port_stop(ap);
+        if (ap->ops->port_stop)
+                ap->ops->port_stop(ap);
         kfree(ap);
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_destroy);