Index: dev/pci/qle.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/qle.c,v
retrieving revision 1.35
diff -u -p -r1.35 qle.c
--- dev/pci/qle.c	14 Mar 2015 03:38:49 -0000	1.35
+++ dev/pci/qle.c	5 Jul 2015 01:02:56 -0000
@@ -72,7 +72,7 @@ int qledebug = QLE_D_PORT;
 #define QLE_MAX_TARGETS			2048
 
 /* maximum number of segments allowed for in a single io */
-#define QLE_MAX_SEGS			16
+#define QLE_MAX_SEGS			32
 
 enum qle_isp_gen {
 	QLE_GEN_ISP24XX = 1,
@@ -2572,11 +2572,6 @@ qle_put_cmd(struct qle_softc *sc, void *
 			    dmap->dm_segs[0].ds_len);
 		} else {
 			flags |= QLE_IOCB_CTRL_FLAG_EXT_SEG;
-			qle_sge(&req->req_data_seg,
-			    QLE_DMA_DVA(sc->sc_segments) +
-			     ccb->ccb_seg_offset,
-			    (ccb->ccb_dmamap->dm_nsegs + 1) *
-			     sizeof(struct qle_iocb_seg));
 
 			for (seg = 0; seg < dmap->dm_nsegs; seg++) {
 				qle_sge(&ccb->ccb_segs[seg],
@@ -2587,11 +2582,15 @@ qle_put_cmd(struct qle_softc *sc, void *
 
 			bus_dmamap_sync(sc->sc_dmat,
 			    QLE_DMA_MAP(sc->sc_segments), ccb->ccb_seg_offset,
-			    sizeof(*ccb->ccb_segs) * ccb->ccb_dmamap->dm_nsegs,
+			    seg * sizeof(*ccb->ccb_segs),
 			    BUS_DMASYNC_PREWRITE);
+
+			qle_sge(&req->req_data_seg,
+			    QLE_DMA_DVA(sc->sc_segments) + ccb->ccb_seg_offset,
+			    seg * sizeof(struct qle_iocb_seg));
 		}
 
-		htolem16(&req->req_data_seg_count, dmap->dm_nsegs);
+		htolem16(&req->req_data_seg_count, dmap->dm_nsegs); /* +1 ? */
 		htolem32(&req->req_data_len, xs->datalen);
 		htolem16(&req->req_ctrl_flags, flags);
 	}
@@ -2887,7 +2886,7 @@ qle_alloc_ccbs(struct qle_softc *sc)
 		ccb = &sc->sc_ccbs[i];
 
 		if (bus_dmamap_create(sc->sc_dmat, MAXPHYS,
-		    QLE_MAX_SEGS, MAXPHYS, 0,
+		    QLE_MAX_SEGS - 1, MAXPHYS, 0,
 		    BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
 		    &ccb->ccb_dmamap) != 0) {
 			printf("%s: unable to create dma map\n", DEVNAME(sc));
Index: scsi/scsi_base.c
===================================================================
RCS file: /cvs/src/sys/scsi/scsi_base.c,v
retrieving revision 1.221
diff -u -p -r1.221 scsi_base.c
--- scsi/scsi_base.c	7 Jun 2015 19:13:27 -0000	1.221
+++ scsi/scsi_base.c	5 Jul 2015 01:02:56 -0000
@@ -1299,15 +1299,44 @@ scsi_xs_exec(struct scsi_xfer *xs)
 void
 scsi_done(struct scsi_xfer *xs)
 {
+	struct scsi_link *link = xs->sc_link;
+	extern int ticks;
+
 #ifdef SCSIDEBUG
-	if (xs->sc_link->flags & SDEV_DB1) {
+	if (xs->link->flags & SDEV_DB1) {
 		if (xs->datalen && (xs->flags & SCSI_DATA_IN))
 			scsi_show_mem(xs->data, min(64, xs->datalen));
 	}
 #endif /* SCSIDEBUG */
-
 	SET(xs->flags, ITSDONE);
+
+	if (xs->error == XS_NOERROR) {
+		switch (xs->status) {
+		case SCSI_BUSY:
+		case SCSI_QUEUE_FULL:
+			xs->error = XS_BUSY;
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* XXX locking */
 	KERNEL_LOCK();
+	if (xs->error == XS_BUSY)
+		link->adj_qfull++;
+
+	if (ticks - link->adj_tick > hz / 4) {
+		if (link->adj_qfull > 8) {
+			if (link->openings > 1)
+				link->openings /= 2;
+		} else if (link->adj_qfull == 0) {
+			if (link->openings < link->hardopenings)
+				link->openings++;
+		}
+		link->adj_tick = ticks;
+	}
+
 	xs->done(xs);
 	KERNEL_UNLOCK();
 }
Index: scsi/scsiconf.c
===================================================================
RCS file: /cvs/src/sys/scsi/scsiconf.c,v
retrieving revision 1.192
diff -u -p -r1.192 scsiconf.c
--- scsi/scsiconf.c	7 Jun 2015 19:13:27 -0000	1.192
+++ scsi/scsiconf.c	5 Jul 2015 01:02:56 -0000
@@ -897,6 +897,8 @@ scsi_probedev(struct scsibus_softc *scsi
 		SET(sc_link->flags, SDEV_OWN_IOPL);
 	}
 
+	sc_link->hardopenings = sc_link->openings;
+
 	/*
 	 * Tell drivers that are paying attention to avoid sync/wide/tags until
 	 * INQUIRY data has been processed and the quirks information is
Index: scsi/scsiconf.h
===================================================================
RCS file: /cvs/src/sys/scsi/scsiconf.h,v
retrieving revision 1.163
diff -u -p -r1.163 scsiconf.h
--- scsi/scsiconf.h	7 Jun 2015 19:13:27 -0000	1.163
+++ scsi/scsiconf.h	5 Jul 2015 01:02:56 -0000
@@ -336,6 +336,10 @@ struct scsi_link {
 	struct	scsi_runq queue;
 	u_int	running;
 	u_short	pending;
+	u_short	hardopenings;
+
+	int	adj_tick;
+	u_int	adj_qfull;
 
 	struct	scsi_iopool *pool;
 };
Index: scsi/sd.c
===================================================================
RCS file: /cvs/src/sys/scsi/sd.c,v
retrieving revision 1.261
diff -u -p -r1.261 sd.c
--- scsi/sd.c	7 Jun 2015 19:13:27 -0000	1.261
+++ scsi/sd.c	5 Jul 2015 01:02:56 -0000
@@ -736,11 +736,12 @@ sd_buf_done(struct scsi_xfer *xs)
 		goto retry;
 
 	case XS_BUSY:
-		if (xs->retries) {
-			if (scsi_delay(xs, 1) != ERESTART)
-				xs->retries = 0;
-		}
-		goto retry;
+		disk_unbusy(&sc->sc_dk, bp->b_bcount,
+		    bp->b_flags & B_READ);
+		bufq_requeue(&sc->sc_bufq, bp);
+		scsi_xs_put(xs);
+		scsi_xsh_add(&sc->sc_xsh);
+		return;
 
 	case XS_TIMEOUT:
 retry: