[PATCH] ALSA: hda/realtek: Fix ALC700 audio on Intel Hades Canyon

[Csaba Budai <ilyr73@gmail.com>]

On Intel Hades Canyon systems with an ALC700 codec, analog audio can
become unusable after rebooting from Windows into Linux.

The affected system uses codec subsystem ID 8086:2073. In the broken
state, Realtek coefficient 0x1b has value 0x4a4b. Setting bit 0x0400
changes it to 0x4e4b and immediately restores normal analog playback.

The BIOS also sets this bit after disabling and re-enabling onboard
audio, while Windows may leave it cleared. Linux currently does not
restore it during codec initialization.

Add a machine-specific fixup for Intel Hades Canyon which sets only
bit 0x0400 of coefficient 0x1b during HDA_FIXUP_ACT_INIT.

The fix has been verified across Windows -> Linux reboots on an Intel
NUC8i7HNB with an ALC700 codec.

Signed-off-by: Csaba Budai <ilyr73@gmail.com>
---
 sound/hda/codecs/realtek/alc269.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/sound/hda/codecs/realtek/alc269.c b/sound/hda/codecs/realtek/alc269.c
index cae327e1d..2fd11b963 100644
--- a/sound/hda/codecs/realtek/alc269.c
+++ b/sound/hda/codecs/realtek/alc269.c
@@ -4089,6 +4089,7 @@ enum {
 	ALC225_FIXUP_DELL_WYSE_MIC_NO_PRESENCE,
 	ALC225_FIXUP_S3_POP_NOISE,
 	ALC700_FIXUP_INTEL_REFERENCE,
+	ALC700_FIXUP_INTEL_HADES_CANYON,
 	ALC274_FIXUP_DELL_BIND_DACS,
 	ALC274_FIXUP_DELL_AIO_LINEOUT_VERB,
 	ALC298_FIXUP_TPT470_DOCK_FIX,
@@ -4333,6 +4334,19 @@ static void alc287_fixup_lenovo_yoga_book_9i(struct hda_codec *codec,
 	__snd_hda_apply_fixup(codec, id, action, 0);
 }
 
+static void alc700_fixup_intel_hades_canyon(struct hda_codec *codec,
+					    const struct hda_fixup *fix,
+					    int action)
+{
+	/*
+	 * Windows may leave coef 0x1b bit 0x0400 cleared, causing broken
+	 * analog playback after rebooting into Linux.  Restore the bit
+	 * during codec initialization.
+	 */
+	if (action == HDA_FIXUP_ACT_INIT)
+		alc_update_coef_idx(codec, 0x1b, 0x0400, 0x0400);
+}
+
 static const struct hda_fixup alc269_fixups[] = {
 	[ALC298_FIXUP_RAZER_BLADE16_2025_PINS] = {
 		.type = HDA_FIXUP_PINS,
@@ -5411,6 +5425,10 @@ static const struct hda_fixup alc269_fixups[] = {
 			{}
 		}
 	},
+	[ALC700_FIXUP_INTEL_HADES_CANYON] = {
+		.type = HDA_FIXUP_FUNC,
+		.v.func = alc700_fixup_intel_hades_canyon,
+	},
 	[ALC274_FIXUP_DELL_BIND_DACS] = {
 		.type = HDA_FIXUP_FUNC,
 		.v.func = alc274_fixup_bind_dacs,
@@ -8230,6 +8248,8 @@ static const struct hda_quirk alc269_fixup_tbl[] = {
 	SND_PCI_QUIRK(0x2782, 0xa128, "Positivo N15RPE-S", ALC269_FIXUP_LIMIT_INT_MIC_BOOST),
 	SND_PCI_QUIRK(0x2782, 0xa212, "Lunnen Ground 14", ALC269VC_FIXUP_LUNNEN_GROUND_14),
 	SND_PCI_QUIRK(0x7017, 0x2014, "Star Labs StarFighter", ALC233_FIXUP_STARLABS_STARFIGHTER),
+	SND_PCI_QUIRK(0x8086, 0x2073, "Intel NUC 8 Hades Canyon",
+		      ALC700_FIXUP_INTEL_HADES_CANYON),
 	SND_PCI_QUIRK(0x8086, 0x2074, "Intel NUC 8", ALC233_FIXUP_INTEL_NUC8_DMIC),
 	SND_PCI_QUIRK(0x8086, 0x2080, "Intel NUC 8 Rugged", ALC256_FIXUP_INTEL_NUC8_RUGGED),
 	SND_PCI_QUIRK(0x8086, 0x2081, "Intel NUC 10", ALC256_FIXUP_INTEL_NUC10),
-- 
2.43.0