From b70870c38ede2bb5b0a738f2f69de145a1931a00 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 24 Nov 2014 15:36:19 +0100
Subject: scsi: never drop to untagged mode during queue ramp down

Dropping to untagged mode when ramping down a queue due to QUEUE FULL
events has two problems:

 - nothing in the midlayer or drivers ever moves back to tagged mode
   during queue ramp up.
 - cmd_per_lun isn't the untagged queue depth for many modern drivers
   that can handle multiple untagged commands, and this is the only
   place in the midlayer assuming that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 72282ae..6b0d524 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -820,12 +820,6 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
 
 	if (sdev->last_queue_full_count <= 10)
 		return 0;
-	if (sdev->last_queue_full_depth < 8) {
-		/* Drop back to untagged */
-		scsi_set_tag_type(sdev, 0);
-		scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun);
-		return -1;
-	}
 
 	return scsi_change_queue_depth(sdev, depth);
 }
-- 
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