Index: i386/i386/busdma_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/i386/busdma_machdep.c,v
retrieving revision 1.32
diff -u -r1.32 busdma_machdep.c
--- i386/i386/busdma_machdep.c	4 Feb 2003 16:30:27 -0000	1.32
+++ i386/i386/busdma_machdep.c	16 Feb 2003 02:21:08 -0000
@@ -403,11 +403,8 @@
 {
 	vm_offset_t		vaddr;
 	vm_offset_t		paddr;
-#ifdef __GNUC__
-	bus_dma_segment_t	dm_segments[dmat->nsegments];
-#else
-	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
-#endif
+	bus_dma_segment_t	stack_dm_segments[BUS_DMAMAP_NSEGS];
+	bus_dma_segment_t      *dm_segments;
 	bus_dma_segment_t      *sg;
 	int			seg;
 	int			error;
@@ -463,6 +460,14 @@
 		splx(s);
 	}
 
+	if (dmat->nsegments > BUS_DMAMAP_NSEGS) {
+		dm_segments = malloc(dmat->nsegments * sizeof(bus_dma_segment_t), 
+		    M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : 0);
+		if (dm_segments == NULL)
+			return ENOMEM;
+	} else
+		dm_segments = stack_dm_segments;
+
 	vaddr = (vm_offset_t)buf;
 	sg = &dm_segments[0];
 	seg = 1;
@@ -484,7 +489,8 @@
 		if (sg->ds_len == 0) {
 			sg->ds_addr = paddr;
 			sg->ds_len = size;
-		} else if (paddr == nextpaddr) {
+		} else if (paddr == nextpaddr && 
+		    sg->ds_len + size < dmat->maxsegsz) {
 			sg->ds_len += size;
 		} else {
 			/* Go to the next segment */
@@ -508,6 +514,9 @@
 	}
 
 	(*callback)(callback_arg, dm_segments, seg, error);
+
+	if (dm_segments != stack_dm_segments)
+		free(dm_segments, M_DEVBUF);
 
 	return (0);
 }