General Questions • Microphone doesn't work with Intel Corporation Alder Lake PCH-P High Definition Audio Controller [8086:51c8]

I can mark this issue as Solved, but, before that, I would like some explanations to this issue. For example: What am I doing when switching the microphone selected in this image? What are all the devices appearing in Input Devices in the image in the previous post? What is doing the solution provided of including the line

Code:

options snd-sof-pci tplg_filename=sof-hda-generic-2ch-pdm1.tplg

in /etc/modprobe.d/micfix.conf?

Thank you for the comprehensive information supplied, and well done on the excellent detective work!

To answer the second question first, the .tplg extension is an abbreviation of topology (the way the parts of something are organized or connected). The file tells the kernel what microphones are present and how they are connected.

The working file tells the kernel that two digital microphones connected 2ch=2 channel, I believe.

Audacity has options to access the microphone directly or through PulseAudio. Default is the option Audacity will use by preference, unless the user choses another option.

The PulseAudio options seem to be for internal and headphone microphone. If you switched from Headphones to get it working, it looks like PulseAudio wrongly believes there are headphones connected with a microphone.

The topology problem I would guess is the result of the BIOS wrongly informing the kernel of the microphone setup. This problem is quite common where laptop manufactures know the sound driver in Windows knows the microphone setup and aren't particularly bother about Linux compatibility. I don't know if this explains the PulseAudio problem. PulseAudio should recognise that the headphone socket is not in use (unplugged).

It may be an issue in the alsa-ucm-conf file used by SOF.

Alsa Use Case Manager describes how to set up the mixer for certain usecases (like "playing audio", "calling"). It also describes how to modify the mixer state to route audio to certain outputs and inputs and how to control those devices.

https://wiki.postmarketos.org/wiki/Alsa_UCM

Bugs in topology and UCM are fixed in updates in Testing. It would be useful to try a live image of Debian Testing. If everything works out of the box, we will know if the issue has been fixed. If the microphone is still broken, it would be helpful if you could file a Debian bug report if one does not exist.

Statistics: Posted by FreewheelinFrank — 2024-11-13 07:05 — Replies 3 — Views 52

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