--- zzzz-none-000/linux-3.10.107/sound/drivers/opl3/opl3_midi.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/sound/drivers/opl3/opl3_midi.c	2021-02-04 17:41:59.000000000 +0000
@@ -105,6 +105,8 @@
 		int pitchbend = chan->midi_pitchbend;
 		int segment;
 
+		if (pitchbend < -0x2000)
+			pitchbend = -0x2000;
 		if (pitchbend > 0x1FFF)
 			pitchbend = 0x1FFF;
 
@@ -258,12 +260,10 @@
 	spin_unlock_irqrestore(&opl3->voice_lock, flags);
 
 	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
-	if (again) {
-		opl3->tlist.expires = jiffies + 1;	/* invoke again */
-		add_timer(&opl3->tlist);
-	} else {
+	if (again)
+		mod_timer(&opl3->tlist, jiffies + 1);	/* invoke again */
+	else
 		opl3->sys_timer_status = 0;
-	}
 	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
 }
 
@@ -275,8 +275,7 @@
 	unsigned long flags;
 	spin_lock_irqsave(&opl3->sys_timer_lock, flags);
 	if (! opl3->sys_timer_status) {
-		opl3->tlist.expires = jiffies + 1;
-		add_timer(&opl3->tlist);
+		mod_timer(&opl3->tlist, jiffies + 1);
 		opl3->sys_timer_status = 1;
 	}
 	spin_unlock_irqrestore(&opl3->sys_timer_lock, flags);
@@ -390,6 +389,11 @@
 		voice = snd_opl3_oss_map[chan->number];		
 	}
 
+	if (voice < 0) {
+		spin_unlock_irqrestore(&opl3->voice_lock, flags);
+		return;
+	}
+
 	if (voice < MAX_OPL2_VOICES) {
 		/* Left register block for voices 0 .. 8 */
 		reg_side = OPL3_LEFT;