Really correct ncr_freeze_devq now. We scan backwards from the current

insertion point into the start queue looking for entries to remove and
mark them with the 'skip' address, recording the entry furthest from the
insertion point that needs to be removed.  We then go through a second
loop starting at the furthest entry to be removed and compress the start
queue.  The old algorithm started at (old insert point + 1) and wrapped
through the whole queue which would end up moving the start position in
the queue out from under the nose of the scrip processor.

1 files changed, 26 insertions, 11 deletions

diff --git a/sys/pci/ncr.c b/sys/pci/ncr.c
index 7a0e12f..193039f 100644
--- a/sys/pci/ncr.c
+++ b/sys/pci/ncr.c
@@ -1,6 +1,6 @@
 /**************************************************************************
 **
-**  $Id: ncr.c,v 1.127 1998/09/16 22:46:04 gibbs Exp $
+**  $Id: ncr.c,v 1.128 1998/09/17 00:08:23 gibbs Exp $
 **
 **  Device driver for the   NCR 53C8XX   PCI-SCSI-Controller Family.
 **
@@ -1288,7 +1288,7 @@ static	void	ncr_attach	(pcici_t tag, int unit);
 
 
 static char ident[] =
-	"\n$Id: ncr.c,v 1.127 1998/09/16 22:46:04 gibbs Exp $\n";
+	"\n$Id: ncr.c,v 1.128 1998/09/17 00:08:23 gibbs Exp $\n";
 
 static const u_long	ncr_version = NCR_VERSION	* 11
 	+ (u_long) sizeof (struct ncb)	*  7
@@ -4594,8 +4594,9 @@ static void
 ncr_freeze_devq (ncb_p np, struct cam_path *path)
 {
 	nccb_p	cp;
-	int	count;
 	int	i;
+	int	count;
+	int	firstskip;
 	/*
 	**	Starting at the first nccb and following
 	**	the links, complete all jobs that match
@@ -4604,6 +4605,7 @@ ncr_freeze_devq (ncb_p np, struct cam_path *path)
 
 	cp = np->link_nccb;
 	count = 0;
+	firstskip = 0;
 	while (cp) {
 		switch (cp->host_status) {
 
@@ -4614,10 +4616,21 @@ ncr_freeze_devq (ncb_p np, struct cam_path *path)
 			 && (xpt_path_comp(path, cp->ccb->ccb_h.path) >= 0)) {
 
 				/* Mark for removal from the start queue */
-				for (i = 0; i < MAX_START; i++) {
-					if (np->squeue[i] == CCB_PHYS(cp, phys))
-						np->squeue[i] =
+				for (i = 1; i < MAX_START; i++) {
+					int idx;
+
+					idx = np->squeueput - i;
+				
+					if (idx < 0)
+						idx = MAX_START + idx;
+					if (np->squeue[idx]
+					 == CCB_PHYS(cp, phys)) {
+						np->squeue[idx] =
 						    NCB_SCRIPT_PHYS (np, skip);
+						if (i > firstskip)
+							firstskip = i;
+						break;
+					}
 				}
 				cp->host_status=HS_STALL;
 				ncr_complete (np, cp);
@@ -4637,21 +4650,24 @@ ncr_freeze_devq (ncb_p np, struct cam_path *path)
 		/* Compress the start queue */
 		j = 0;
 		bidx = np->squeueput;
-		for (i = (np->squeueput + 1) % MAX_START;;
-		     i = (i + 1) % MAX_START) {
+		i = np->squeueput - firstskip;
+		if (i < 0)
+			i = MAX_START + i;
+		for (;;) {
 
 			bidx = i - j;
 			if (bidx < 0)
 				bidx = MAX_START + bidx;
 			
-			if (np->squeue[i] == NCB_SCRIPT_PHYS (np, skip))
+			if (np->squeue[i] == NCB_SCRIPT_PHYS (np, skip)) {
 				j++;
-			else if (j != 0) {
+			} else if (j != 0) {
 				np->squeue[bidx] = np->squeue[i];
 				if (np->squeue[bidx]
 				 == NCB_SCRIPT_PHYS(np, idle))
 					break;
 			}
+			i = (i + 1) % MAX_START;
 		}
 		np->squeueput = bidx;
 	}
@@ -5631,7 +5647,6 @@ static void ncr_int_ma (ncb_p np, u_char dstat)
 	/*
 	**	locate matching cp
 	*/
-	dsa = INL (nc_dsa);
 	cp = np->link_nccb;
 	while (cp && (CCB_PHYS (cp, phys) != dsa))
 		cp = cp->link_nccb;