Regression in Linux Kernel v5.15.71 / external headset microphone stops working

[Jan Henke]

Hello sound system maintainers,

a recent patch to the stable 5.15 linux branch unfortunately introduced 
a regression. From 5.15.71 onward (also in 5.19.15) plugging in an 
external headset into the audio jack no longer results in a working 
microphone. Symptoms are that there is no choice to set the connected 
device to microphone only (I am using GNOME, so once you plugin a device 
you get a dialogue to choose it's type, normally there are 3 choices, 
Headphone, Headset and Microphone, with the bug the last one is 
missing), and the connected microphone no longer records any audio. Note 
that you can still choose the headset microphone as audio input, it just 
does not record anything.

Doing a git bisect I was able to identify the commit introducing this 
regression:

a963fe6d0eb6ef0a15b3aade7c186cd5bb7bd01f is the first bad commit
commit a963fe6d0eb6ef0a15b3aade7c186cd5bb7bd01f
Author: Callum Osmotherly <callum.osmotherly at gmail.com>
Date:   Thu Sep 15 22:36:08 2022 +0930

     ALSA: hda/realtek: Enable 4-speaker output Dell Precision 5530 laptop
     
     commit 1885ff13d4c42910b37a0e3f7c2f182520f4eed1 upstream.
     
     Just as with the 5570 (and the other Dell laptops), this enables the two
     subwoofer speakers on the Dell Precision 5530 together with the main
     ones, significantly increasing the audio quality. I've tested this
     myself on a 5530 and can confirm it's working as expected.
     
     Signed-off-by: Callum Osmotherly <callum.osmotherly at gmail.com>
     Cc: <stable at vger.kernel.org>
     Link:https://lore.kernel.org/r/YyMjQO3mhyXlMbCf@piranha
     Signed-off-by: Takashi Iwai <tiwai at suse.de>
     Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

  sound/pci/hda/patch_realtek.c | 1 +
  1 file changed, 1 insertion(+)

Which makes sense, since I noticed this regression on a Dell Precision 
5530 laptop.

Downstream bug report: https://bugs.gentoo.org/876843

Please revert this commit to restore the previous working condition on 
all affected branches, since an external headset is a very common use 
case with these kinds of laptops. There were similar commits for 
different laptop models, but I do not have any of these models, so I 
cannot say if they cause a similar regression.

Best regards,
Jan Henke