scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 5 insertions, 20 deletions

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index a3426f1bf0dd..106fa2f886d2 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -744,8 +744,6 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
 /**
  * scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
  * @sdev: SCSI Device in question
- * @tagged: Do we use tagged queueing (non-0) or do we treat
- *          this device as an untagged device (0)
  * @tags: Number of tags allowed if tagged queueing enabled,
  *        or number of commands the low level driver can
  *        queue up in non-tagged mode (as per cmd_per_lun).
@@ -759,7 +757,7 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
  *              currently active and whether or not it even has the
  *              command blocks built yet.
  */
-void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
+void scsi_adjust_queue_depth(struct scsi_device *sdev, int tags)
 {
         unsigned long flags;
 
@@ -787,20 +785,6 @@ void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
         }
 
         sdev->queue_depth = tags;
-        switch (tagged) {
-                case 0:
-                        sdev->simple_tags = 0;
-                        break;
-                case MSG_ORDERED_TAG:
-                case MSG_SIMPLE_TAG:
-                        sdev->simple_tags = 1;
-                        break;
-                default:
-                        sdev->simple_tags = 0;
-                        sdev_printk(KERN_WARNING, sdev,
-                                    "scsi_adjust_queue_depth, bad queue type, "
-                                    "disabled\n");
-        }
  out:
         spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 }
@@ -848,11 +832,12 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
                 return 0;
         if (sdev->last_queue_full_depth < 8) {
                 /* Drop back to untagged */
-                scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
+                scsi_set_tag_type(sdev, 0);
+                scsi_adjust_queue_depth(sdev, sdev->host->cmd_per_lun);
                 return -1;
         }
 
-        scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
+        scsi_adjust_queue_depth(sdev, depth);
         return depth;
 }
 EXPORT_SYMBOL(scsi_track_queue_full);
@@ -867,7 +852,7 @@ int scsi_change_queue_type(struct scsi_device *sdev, int tag_type)
         if (!sdev->tagged_supported)
                 return 0;
 
-        scsi_adjust_queue_depth(sdev, tag_type, sdev->queue_depth);
+        scsi_set_tag_type(sdev, tag_type);
         return tag_type;
 
 }