ALSA: hda/realtek: Fix microphone regression on ASUS N705UD

This fixes a regression introduced a few weeks ago in stable kernels
6.12.14 and 6.13.3. The internal microphone on ASUS Vivobook N705UD /
X705UD laptops is broken: the microphone appears in userspace (e.g.
Gnome settings) but no sound is detected.
I bisected it to commit 3b4309546b48 ("ALSA: hda: Fix headset detection
failure due to unstable sort").

I figured out the cause:
1. The initial pins enabled for the ALC256 driver are:
       cfg->inputs == {
         { pin=0x19, type=AUTO_PIN_MIC,
           is_headset_mic=1, is_headphone_mic=0, has_boost_on_pin=1 },
         { pin=0x1a, type=AUTO_PIN_MIC,
           is_headset_mic=0, is_headphone_mic=0, has_boost_on_pin=1 } }
2. Since 2017 and commits c1732ede5e8 ("ALSA: hda/realtek - Fix headset
   and mic on several ASUS laptops with ALC256") and 28e8af8a163 ("ALSA:
   hda/realtek: Fix mic and headset jack sense on ASUS X705UD"), the
   quirk ALC256_FIXUP_ASUS_MIC is also applied to ASUS X705UD / N705UD
   laptops.
   This added another internal microphone on pin 0x13:
       cfg->inputs == {
         { pin=0x13, type=AUTO_PIN_MIC,
           is_headset_mic=0, is_headphone_mic=0, has_boost_on_pin=1 },
         { pin=0x19, type=AUTO_PIN_MIC,
           is_headset_mic=1, is_headphone_mic=0, has_boost_on_pin=1 },
         { pin=0x1a, type=AUTO_PIN_MIC,
           is_headset_mic=0, is_headphone_mic=0, has_boost_on_pin=1 } }
   I don't know what this pin 0x13 corresponds to. To the best of my
   knowledge, these laptops have only one internal microphone.
3. Before 2025 and commit 3b4309546b48 ("ALSA: hda: Fix headset
   detection failure due to unstable sort"), the sort function would let
   the microphone of pin 0x1a (the working one) *before* the microphone
   of pin 0x13 (the phantom one).
4. After this commit 3b4309546b48, the fixed sort function puts the
   working microphone (pin 0x1a) *after* the phantom one (pin 0x13). As
   a result, no sound is detected anymore.

It looks like the quirk ALC256_FIXUP_ASUS_MIC is not needed anymore for
ASUS Vivobook X705UD / N705UD laptops. Without it, everything works
fine:
- the internal microphone is detected and records actual sound,
- plugging in a jack headset is detected and can record actual sound
  with it,
- unplugging the jack headset makes the system go back to internal
  microphone and can record actual sound.

Cc: stable@vger.kernel.org
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Chris Chiu <chris.chiu@canonical.com>
Fixes: 3b4309546b48 ("ALSA: hda: Fix headset detection failure due to unstable sort")
Tested-by: Adrien Vergé <adrienverge@gmail.com>
Signed-off-by: Adrien Vergé <adrienverge@gmail.com>
Link: https://patch.msgid.link/20250226135515.24219-1-adrienverge@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

0 files changed, 0 insertions, 0 deletions