diff -ur --exclude-from /home/axboe/cdrom/exclude /opt/kernel/linux-2.4.2-ac7/drivers/scsi/hosts.h linux/drivers/scsi/hosts.h
--- /opt/kernel/linux-2.4.2-ac7/drivers/scsi/hosts.h	Thu Mar  1 15:46:16 2001
+++ linux/drivers/scsi/hosts.h	Mon Feb 26 14:22:58 2001
@@ -242,6 +242,11 @@
     short unsigned int sg_tablesize;
 
     /*
+     * if the host adapter has limitations beside segment count
+     */
+    short unsigned int max_sectors;
+
+    /*
      * True if this host adapter can make good use of linked commands.
      * This will allow more than one command to be queued to a given
      * unit on a given host.  Set this to the maximum number of command
@@ -379,6 +384,7 @@
     int can_queue;
     short cmd_per_lun;
     short unsigned int sg_tablesize;
+    short unsigned int max_sectors;
 
     unsigned in_recovery:1;
     unsigned unchecked_isa_dma:1;
diff -ur --exclude-from /home/axboe/cdrom/exclude /opt/kernel/linux-2.4.2-ac7/drivers/scsi/scsi_merge.c linux/drivers/scsi/scsi_merge.c
--- /opt/kernel/linux-2.4.2-ac7/drivers/scsi/scsi_merge.c	Fri Feb  9 20:30:23 2001
+++ linux/drivers/scsi/scsi_merge.c	Mon Feb 26 14:24:33 2001
@@ -417,6 +417,10 @@
 		max_segments = 64;
 #endif
 
+	if (SHpnt->max_sectors
+	    && (req->nr_sectors + (bh->b_size >> 9)) > SHpnt->max_sectors)
+		return 0;
+
 	if (use_clustering) {
 		/* 
 		 * See if we can do this without creating another
@@ -473,6 +477,10 @@
 		max_segments = 64;
 #endif
 
+	if (SHpnt->max_sectors
+	    && (req->nr_sectors + (bh->b_size >> 9)) > SHpnt->max_sectors)
+		return 0;
+
 	if (use_clustering) {
 		/* 
 		 * See if we can do this without creating another
@@ -624,6 +632,11 @@
 		return 0;
 	}
 #endif
+
+	if (SHpnt->max_sectors
+	    && (req->nr_sectors + next->nr_sectors) > SHpnt->max_sectors)
+		return 0;
+
 	/*
 	 * The main question is whether the two segments at the boundaries
 	 * would be considered one or two.