Index: ds1.c
===================================================================
RCS file: /home/ncvs/src/sys/dev/sound/pci/ds1.c,v
retrieving revision 1.36
diff -u -r1.36 ds1.c
--- ds1.c	2 Sep 2003 17:30:37 -0000	1.36
+++ ds1.c	15 Dec 2003 18:49:02 -0000
@@ -729,8 +729,15 @@
 ds_intr(void *p)
 {
 	struct sc_info *sc = (struct sc_info *)p;
-	u_int32_t i, x;
+	int i, pch, rch;
 
+	/*
+	 * In this particular scenerio, sc->lock only protects
+	 * against hardware access.  Other immutables, like the lock itself and
+	 * the pointers to the pcm channel structure can be accessed safely without
+	 * the lock.
+	 */
+	pch = rch = 0;
 	snd_mtxlock(sc->lock);
 	i = ds_rd(sc, YDSXGR_STATUS, 4);
 	if (i & 0x00008000)
@@ -739,25 +746,26 @@
 		ds_wr(sc, YDSXGR_STATUS, i & 0x80008000, 4);
 		sc->currbank = ds_rd(sc, YDSXGR_CTRLSELECT, 4) & 0x00000001;
 
-		x = 0;
-		for (i = 0; i < DS1_CHANS; i++) {
-			if (sc->pch[i].run) {
-				x = 1;
-				chn_intr(sc->pch[i].channel);
-			}
-		}
-		for (i = 0; i < 2; i++) {
-			if (sc->rch[i].run) {
-				x = 1;
-				chn_intr(sc->rch[i].channel);
-			}
-		}
+		for (i = 0; i < DS1_CHANS; i++)
+			if (sc->pch[i].run)
+				pch |= 1<<i;
+		for (i = 0; i < 2; i++)
+			if (sc->rch[i].run)
+				rch |= 1<<i;
 		i = ds_rd(sc, YDSXGR_MODE, 4);
-		if (x)
+		if ( pch || rch )
 			ds_wr(sc, YDSXGR_MODE, i | 0x00000002, 4);
 
 	}
 	snd_mtxunlock(sc->lock);
+
+	for (i = 0; i<DS1_CHANS; i++)
+		if ( pch & (1<<i) )
+			chn_intr(sc->pch[i].channel);
+	
+	for (i = 0; i<2; i++)
+		if ( rch & (1<<i) )
+			chn_intr(sc->rch[i].channel);
 }
 
 /* -------------------------------------------------------------------- */