svn commit: r254615 - head/sys/dev/mps

[Kenneth D. Merry]

Author: ken
Date: Wed Aug 21 21:30:56 2013
New Revision: 254615
URL: http://svnweb.freebsd.org/changeset/base/254615

Log:
  Fix mps(4) driver breakage that came in in change 253550 that
  manifested itself in out of chain frame conditions.
  
  When the driver ran out of chain frames, the request in question
  would get completed early, and go through mpssas_scsiio_complete().
  
  In mpssas_scsiio_complete(), the negation of the CAM status values
  (CAM_STATUS_MASK | CAM_SIM_QUEUED) was ORed in instead of being
  ANDed in.  This resulted in a bogus CAM CCB status value.  This
  didn't show up in the non-error case, because the status was reset
  to something valid (e.g. CAM_REQ_CMP) later on in the function.
  
  But in the error case, such as when the driver ran out of chain
  frames, the CAM_REQUEUE_REQ status was ORed in to the bogus status
  value.  This led to the CAM transport layer repeatedly releasing
  the SIM queue, because it though that the CAM_RELEASE_SIMQ flag had
  been set.  The symptom was messages like this on the console when
  INVARIANTS were enabled:
  
  xpt_release_simq: requested 1 > present 0
  xpt_release_simq: requested 1 > present 0
  xpt_release_simq: requested 1 > present 0
  
  mps_sas.c:	In mpssas_scsiio_complete(), use &= to take status
  		bits out.  |= adds them in.
  
  		In the error case in mpssas_scsiio_complete(), set
  		the status to CAM_REQUEUE_REQ, don't OR it in.
  
  MFC after:	3 days
  Sponsored by:	Spectra Logic

Modified:
  head/sys/dev/mps/mps_sas.c

Modified: head/sys/dev/mps/mps_sas.c
==============================================================================
--- head/sys/dev/mps/mps_sas.c	Wed Aug 21 21:30:06 2013	(r254614)
+++ head/sys/dev/mps/mps_sas.c	Wed Aug 21 21:30:56 2013	(r254615)
@@ -2103,7 +2103,7 @@ mpssas_scsiio_complete(struct mps_softc 
 	cm->cm_targ->completed++;
 	cm->cm_targ->outstanding--;
 	TAILQ_REMOVE(&cm->cm_targ->commands, cm, cm_link);
-	ccb->ccb_h.status |= ~(CAM_STATUS_MASK | CAM_SIM_QUEUED);
+	ccb->ccb_h.status &= ~(CAM_STATUS_MASK | CAM_SIM_QUEUED);
 
 	if (cm->cm_state == MPS_CM_STATE_TIMEDOUT) {
 		TAILQ_REMOVE(&cm->cm_targ->timedout_commands, cm, cm_recovery);
@@ -2145,7 +2145,7 @@ mpssas_scsiio_complete(struct mps_softc 
 		 * because there can be no reply when we haven't actually
 		 * gone out to the hardware.
 		 */
-		ccb->ccb_h.status |= CAM_REQUEUE_REQ;
+		ccb->ccb_h.status = CAM_REQUEUE_REQ;
 
 		/*
 		 * Currently the only error included in the mask is