From 8e9b01db2c51baf1a5093b7dded6335187cd51a6 Mon Sep 17 00:00:00 2001
From: krw <krw@openbsd.org>
Date: Wed, 17 Aug 2016 01:02:31 +0000
Subject: [PATCH] Make error handling (esp. DATA_UNDERRUN) clearer and avoid
 losing resid value.

Specs from mikeb@, ok dlg@
---
 sys/dev/ic/mpi.c   | 15 ++++++++-------
 sys/dev/pci/mpii.c | 28 ++++++++++------------------
 2 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/sys/dev/ic/mpi.c b/sys/dev/ic/mpi.c
index 3689881f254..1234a88f546 100644
--- a/sys/dev/ic/mpi.c
+++ b/sys/dev/ic/mpi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpi.c,v 1.204 2016/08/14 04:08:03 dlg Exp $ */
+/*	$OpenBSD: mpi.c,v 1.205 2016/08/17 01:02:31 krw Exp $ */
 
 /*
  * Copyright (c) 2005, 2006, 2009 David Gwynne <dlg@openbsd.org>
@@ -1449,20 +1449,21 @@ mpi_scsi_cmd_done(struct mpi_ccb *ccb)
 	DNPRINTF(MPI_D_CMD, "%s:  tag: 0x%04x\n", DEVNAME(sc),
 	    letoh16(sie->tag));
 
-	xs->status = sie->scsi_status;
+	if (sie->scsi_state & MPI_SCSIIO_ERR_STATE_NO_SCSI_STATUS)
+		xs->status = SCSI_TERMINATED;
+	else
+		xs->status = sie->scsi_status;
+	xs->resid = 0;
+
 	switch (lemtoh16(&sie->ioc_status)) {
 	case MPI_IOCSTATUS_SCSI_DATA_UNDERRUN:
 		xs->resid = xs->datalen - lemtoh32(&sie->transfer_count);
-		if (sie->scsi_state & MPI_SCSIIO_ERR_STATE_NO_SCSI_STATUS) {
-			xs->error = XS_DRIVER_STUFFUP;
-			break;
-		}
 		/* FALLTHROUGH */
 	case MPI_IOCSTATUS_SUCCESS:
 	case MPI_IOCSTATUS_SCSI_RECOVERED_ERROR:
 		switch (xs->status) {
 		case SCSI_OK:
-			xs->resid = 0;
+			xs->error = XS_NOERROR;
 			break;
 
 		case SCSI_CHECK:
diff --git a/sys/dev/pci/mpii.c b/sys/dev/pci/mpii.c
index b6d010dfe88..7e21bd69f21 100644
--- a/sys/dev/pci/mpii.c
+++ b/sys/dev/pci/mpii.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpii.c,v 1.103 2016/08/09 15:04:34 krw Exp $	*/
+/*	$OpenBSD: mpii.c,v 1.104 2016/08/17 01:02:31 krw Exp $	*/
 /*
  * Copyright (c) 2010, 2012 Mike Belopuhov
  * Copyright (c) 2009 James Giannoules
@@ -2918,30 +2918,22 @@ mpii_scsi_cmd_done(struct mpii_ccb *ccb)
 	DNPRINTF(MPII_D_CMD, "%s:  bidirectional_transfer_count: 0x%08x\n",
 	    DEVNAME(sc), letoh32(sie->bidirectional_transfer_count));
 
-	xs->status = sie->scsi_status;
+	if (sie->scsi_state & MPII_SCSIIO_ERR_STATE_NO_SCSI_STATUS)
+		xs->status = SCSI_TERMINATED;
+	else
+		xs->status = sie->scsi_status;
+	xs->resid = 0;
+
 	switch (lemtoh16(&sie->ioc_status) & MPII_IOCSTATUS_MASK) {
 	case MPII_IOCSTATUS_SCSI_DATA_UNDERRUN:
-		switch (xs->status) {
-		case SCSI_OK:
-			xs->resid = xs->datalen -
-			    lemtoh32(&sie->transfer_count);
-			break;
-
-		case SCSI_CHECK:
-			xs->error = XS_SENSE;
-			break;
-
-		default:
-			xs->error = XS_DRIVER_STUFFUP;
-			break;
-		}
-		break;
+		xs->resid = xs->datalen - lemtoh32(&sie->transfer_count);
+		/* FALLTHROUGH */
 
 	case MPII_IOCSTATUS_SUCCESS:
 	case MPII_IOCSTATUS_SCSI_RECOVERED_ERROR:
 		switch (xs->status) {
 		case SCSI_OK:
-			xs->resid = 0;
+			xs->error = XS_NOERROR;
 			break;
 
 		case SCSI_CHECK:
-- 
2.20.1