svn commit: r236803 - stable/8/sys/cam/scsi

[Alexander Motin]

Author: mav
Date: Sat Jun  9 09:08:33 2012
New Revision: 236803
URL: http://svn.freebsd.org/changeset/base/236803

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

Modified:
  stable/8/sys/cam/scsi/scsi_xpt.c
Directory Properties:
  stable/8/sys/   (props changed)

Modified: stable/8/sys/cam/scsi/scsi_xpt.c
==============================================================================
--- stable/8/sys/cam/scsi/scsi_xpt.c	Sat Jun  9 09:04:59 2012	(r236802)
+++ stable/8/sys/cam/scsi/scsi_xpt.c	Sat Jun  9 09:08:33 2012	(r236803)
@@ -293,6 +293,14 @@ 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