From b4b0481b3f8496a57c2672d5b0e3fb0e6ede0837 Mon Sep 17 00:00:00 2001
From: Adrian Siekierka <kontakt@asie.pl>
Date: Sun, 16 Mar 2025 18:32:55 +0100
Subject: [PATCH] swan: fix edge case in APU emulation

---
 src/engine/platform/sound/swan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/engine/platform/sound/swan.c b/src/engine/platform/sound/swan.c
index 822d2509b..2dad25a49 100644
--- a/src/engine/platform/sound/swan.c
+++ b/src/engine/platform/sound/swan.c
@@ -136,7 +136,7 @@ void swan_sound_tick(swan_sound_t *snd, uint32_t cycles) {
                 snd->period_counter[ch] -= step;
 
                 // Update noise counter
-                if (ch == 3 && (snd->ch_ctrl & SND_CH4_NOISE) && (snd->noise_ctrl & SND_NOISE_ENABLE)) {
+                if (ch == 3 && (snd->noise_ctrl & SND_NOISE_ENABLE)) {
                     uint8_t lfsr_new = (1 ^ (snd->noise_lfsr >> 7) ^ (snd->noise_lfsr >> lfsr_tap_bits[snd->noise_ctrl & 7])) & 0x1;
                     snd->noise_lfsr = (snd->noise_lfsr << 1) | lfsr_new;
                 }