From 52e22e90fcd631a9bf8e3b9733e72277a48bf73d Mon Sep 17 00:00:00 2001
From: win2kgamer <47463859+win2kgamer@users.noreply.github.com>
Date: Tue, 21 Oct 2025 20:29:46 -0500
Subject: [PATCH] AD1848: I12 bit 4 is read-only, fixes CODEC detection in OS/2
 driver

---
 src/sound/snd_ad1848.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/sound/snd_ad1848.c b/src/sound/snd_ad1848.c
index 6c32b1892..62c3e35e9 100644
--- a/src/sound/snd_ad1848.c
+++ b/src/sound/snd_ad1848.c
@@ -344,7 +344,7 @@ ad1848_write(uint16_t addr, uint8_t val, void *priv)
 
                 case 12:
                     if (ad1848->type >= AD1848_TYPE_CS4248) {
-                        ad1848->regs[12] = 0x80 | (val & 0x70) | (ad1848->regs[12] & 0x0f);
+                        ad1848->regs[12] = 0x80 | (val & 0x60) | (ad1848->regs[12] & 0x0f);
                         if ((ad1848->type >= AD1848_TYPE_CS4231) && (ad1848->type < AD1848_TYPE_CS4235)) {
                             if (val & 0x40)
                                 ad1848->fmt_mask |= 0x80;