alsa-project/alsa-ucm-conf issue #673 was opened from dniku:
**DISCLOSURE**: the text below was written with heavy assistance from a language model.
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### Summary
On Framework Laptop 16 (AMD Ryzen AI 300 series) with `alsa.mixer_name = "Realtek ALC285"`, `alsa.components = "HDA:10ec0285,f111000d,00100002"`, the generic HDA UCM profile creates a `Headphones` playback device even though the codec exposes no headphone jack/controls. WirePlumber then selects a phantom `Headphones` sink by default (higher UCM priority than `Speaker`), requiring a manual switch to `Speaker`.
Separately: UCM also exposes an HDA “Stereo Microphone” capture path (`Mic2`) which records silence; the real microphone is provided by the ACP/DMIC path.
This is reproducible after wiping WirePlumber state and restarting PipeWire/WirePlumber.
### Hardware / software - Machine: Framework Laptop 16 (AMD Ryzen AI 300 series) - Codec: Realtek ALC285, subsystem id f111:000d - Distro: NixOS 25.11 - PipeWire: 1.4.9 - WirePlumber: 0.5.12 - alsa-ucm-conf: 1.2.14
### Steps to reproduce 1. Ensure you are using the stock alsa-ucm-conf UCM2 files (no overrides). 2. Clear WP state and restart user audio services: ```sh wpctl clear-default rm -rf ~/.local/state/wireplumber systemctl --user restart wireplumber pipewire pipewire-pulse ```
3. Observe the default sink:
```sh wpctl status -n wpctl inspect @DEFAULT_AUDIO_SINK@ ```
### Observed behavior (before fix)
Default sink becomes the phantom Headphones profile:
```sh $ wpctl status -n # ... ├─ Sinks: │ * 59. alsa_output.pci-0000_c2_00.6.HiFi__Headphones__sink [vol: 0.40] ```
```sh $ wpctl inspect @DEFAULT_AUDIO_SINK@ # ... device.profile.name = "HiFi: Headphones: sink" * node.name = "alsa_output.pci-0000_c2_00.6.HiFi__Headphones__sink" ```
But ALSA exposes no headphone controls on that codec/card:
```sh $ amixer -c 2 scontrols Simple mixer control 'Master',0 Simple mixer control 'Speaker',0 Simple mixer control 'Bass Speaker',0 Simple mixer control 'PCM',0
$ amixer -c 2 controls numid=7,iface=CARD,name='Speaker Front Phantom Jack' numid=8,iface=CARD,name='Speaker Surround Phantom Jack' numid=6,iface=MIXER,name='Master Playback Switch' numid=5,iface=MIXER,name='Master Playback Volume' numid=13,iface=MIXER,name='PCM Playback Volume' numid=4,iface=MIXER,name='Bass Speaker Playback Switch' numid=3,iface=MIXER,name='Bass Speaker Playback Volume' numid=2,iface=MIXER,name='Speaker Playback Switch' numid=1,iface=MIXER,name='Speaker Playback Volume' numid=10,iface=PCM,name='Capture Channel Map' numid=9,iface=PCM,name='Playback Channel Map' numid=11,iface=PCM,name='Capture Channel Map',device=2 numid=12,iface=PCM,name='Capture Channel Map',index=1,device=2 ```
The codec dump also contains no “Headphone/Headset” pins:
```sh $ grep -nEi 'Headphone|Headset|Front Headphone' /proc/asound/card2/codec#0 # (no output) ```
### Root cause hypothesis
[`ucm2/HDA/HiFi-analog.conf`](https://github.com/alsa-project/alsa-ucm-conf/blob/5d175e1f7e3df15973945a9cc...) defines `SectionDevice."Headphones"` unconditionally and assigns it `PlaybackPriority 200`, while `Speaker` is `PlaybackPriority 100`. On jackless hardware with no headphone controls/jack, this results in a “Headphones” UCM device that WirePlumber prefers.
Similar problem exists in [`ucm2/HDA/HiFi-mic.conf`](https://github.com/alsa-project/alsa-ucm-conf/blob/5d175e1f7e3df15973945a9cc...)
### Proposed fix
Guard creation of `SectionDevice."Headphones"` so it is only instantiated when relevant headphone controls/jack controls exist (e.g. `Headphone Playback Volume`, `Headphone Playback Switch`, or `iface=CARD,name='Headphone Jack'`).
Similarly guard the HDA analog capture device on this platform when it is not functional, leaving the working ACP/DMIC capture path as the only mic.
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(end of section written with language model assistance)
I have proposed a patch for Framework 16 in https://github.com/NixOS/nixos-hardware/pull/1718. Please see the diagnostics shared in that PR. I would appreciate feedback on the specific workaround that is implemented there from someone familiar with `alsa-ucm-conf`.
For the output of `nix shell nixpkgs#alsa-utils -c alsa-info --no-upload --stdout` before/after applying the patch, as well as the diff between the two, please see [this gist](https://gist.github.com/dniku/d9b5095aef0e926399ebd772d0b40bd0).
Issue URL : https://github.com/alsa-project/alsa-ucm-conf/issues/673 Repository URL: https://github.com/alsa-project/alsa-ucm-conf