From cdb0c4193b101ec7cb2955800b09e001a0bc9b84 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Sat, 25 Mar 2023 04:27:54 -0700
Subject: [PATCH] GBA Audio: Clear GB audio state when disabled

---
 CHANGES         |  1 +
 src/gba/audio.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/CHANGES b/CHANGES
index 0c7a5918b..3b8022655 100644
--- a/CHANGES
+++ b/CHANGES
@@ -7,6 +7,7 @@ Features:
 Emulation fixes:
  - GB Video: Implement DMG-style sprite ordering
  - GBA Audio: Fix improperly deserializing GB audio registers (fixes mgba.io/i/2793)
+ - GBA Audio: Clear GB audio state when disabled
  - GBA Memory: Make VRAM access stalls only apply to BG RAM
  - GBA Overrides: Fix saving in PMD:RRT (JP) (fixes mgba.io/i/2862)
  - GBA SIO: Fix SIOCNT SI pin value after attaching player 2 (fixes mgba.io/i/2805)
diff --git a/src/gba/audio.c b/src/gba/audio.c
index 2c61aa1ce..83c20da7d 100644
--- a/src/gba/audio.c
+++ b/src/gba/audio.c
@@ -231,8 +231,22 @@ void GBAAudioWriteSOUNDCNT_HI(struct GBAAudio* audio, uint16_t value) {
 }
 
 void GBAAudioWriteSOUNDCNT_X(struct GBAAudio* audio, uint16_t value) {
+	GBAAudioSample(audio, mTimingCurrentTime(&audio->p->timing));
 	audio->enable = GBAudioEnableGetEnable(value);
 	GBAudioWriteNR52(&audio->psg, value);
+	if (!audio->enable) {
+		int i;
+		for (i = REG_SOUND1CNT_LO; i < REG_SOUNDCNT_HI; i += 2) {
+			audio->p->memory.io[i >> 1] = 0;
+		}
+		audio->psg.ch3.size = 0;
+		audio->psg.ch3.bank = 0;
+		audio->psg.ch3.volume = 0;
+		audio->volume = 0;
+		audio->volumeChA = 0;
+		audio->volumeChB = 0;
+		audio->p->memory.io[REG_SOUNDCNT_HI >> 1] &= 0xFF00;
+	}
 }
 
 void GBAAudioWriteSOUNDBIAS(struct GBAAudio* audio, uint16_t value) {