svn commit: r231850 - stable/9/sys/cam/scsi

[Justin T. Gibbs]

Author: gibbs
Date: Fri Feb 17 01:23:58 2012
New Revision: 231850
URL: http://svn.freebsd.org/changeset/base/231850

Log:
  MFC r231745:
  
  Limit the ST3146855LW U320 drive to 55 tags to avoid command timeouts
  under load.
  
  Submitted by:	Gelson Borsoi

Modified:
  stable/9/sys/cam/scsi/scsi_xpt.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/cam/scsi/scsi_xpt.c
==============================================================================
--- stable/9/sys/cam/scsi/scsi_xpt.c	Fri Feb 17 01:21:08 2012	(r231849)
+++ stable/9/sys/cam/scsi/scsi_xpt.c	Fri Feb 17 01:23:58 2012	(r231850)
@@ -295,6 +295,14 @@ static struct scsi_quirk_entry scsi_quir
 	},
 	{
 		/*
+		 * Experiences command timeouts under load with a
+		 * tag count higher than 55.
+		 */
+		{ T_DIRECT, SIP_MEDIA_FIXED, seagate, "ST3146855LW", "*"},
+		/*quirks*/0, /*mintags*/2, /*maxtags*/55
+	},
+	{
+		/*
 		 * Slow when tagged queueing is enabled.  Write performance
 		 * steadily drops off with more and more concurrent
 		 * transactions.  Best sequential write performance with