uefi-common: install alsa-ucm-conf so PipeWire can route SOF cards

[igorpecovnik]

The bug

ThinkPad X9-15 (LNL, CS42L43 jack + CS35L56 SPI amps) booted Armbian with kernel-level audio fully alive — `aplay -l` enumerated the Speaker PCM, `speaker-test -D plughw:0,2` made sound. But PipeWire / wireplumber only ever saw "auto_null" — no real sink — because the SOF card has six PCM devices (Jack Out, Speaker, three HDMI, Deepbuffer Jack Out) and userspace has no recipe for which one is the speaker output, which controls to unmute, or how to route on jack insert.

`alsa-ucm-conf` ships those per-card UCM profiles. Without it: "Dummy Output" only. With it: Speaker sink appears, audio works.

The fix

One line in `config/sources/families/include/uefi_common.inc`:

```bash
add_packages_to_image alsa-ucm-conf
```

Architecture: all package, inert on machines without UCM profiles. Lives next to the existing `firmware-sof-signed` line above — same scope, same rationale.

Verified on

Lenovo ThinkPad X9-15 Gen 1 (DMI `21Q6001MGE`, LNL), Armbian edge x86 7.0.9. Same kernel + same SOF firmware + same Cirrus blobs + same topology as a working Ubuntu OEM 6.17 boot of the same machine — the only difference between "silent" and "working" was this package.

Test plan

• Build UEFI x86 desktop on noble / resolute; confirm `dpkg -l alsa-ucm-conf` shows installed
• Boot on any SOF-equipped UEFI laptop (Meteor/Lunar/Panther Lake, recent ThinkPad / Latitude / EliteBook); confirm GNOME Sound shows a Speaker sink instead of Dummy Output
• Confirm no regression on UEFI builds without SOF hardware (cloud VMs, generic UEFI x86 servers) — package is inert there

Summary by CodeRabbit

• Bug Fixes

  • Fixed audio output issue on UEFI x86 laptops where speakers remained silent due to missing per-machine audio routing configuration for SOF audio components.

• Documentation

  • Added documentation explaining audio component detection behavior and fallback scenarios.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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Review profile: CHILL

Plan: Pro

Run ID: 8ec914eb-dfbd-4c80-bd22-55ef848054b3

📥 Commits

Reviewing files that changed from the base of the PR and between b791830 and ca99a43.

📒 Files selected for processing (1)

• config/sources/families/include/uefi_common.inc

---

📝 Walkthrough

Walkthrough

The UEFI common image configuration now includes the alsa-ucm-conf package to ensure proper audio routing on UEFI x86 systems. Documentation explains that without this package, PipeWire and wireplumber may detect audio components but lack machine-specific UCM routing tables, causing silent speaker output via fallback behavior.

Changes

UEFI Audio Configuration

Layer / File(s)	Summary
ALSA UCM configuration dependency config/sources/families/include/uefi_common.inc	The alsa-ucm-conf package is added to the UEFI image via add_packages_to_image, with comments documenting the UCM routing failure mode on affected x86 systems where PipeWire/wireplumber would otherwise select null audio output.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Suggested reviewers

• rpardini

Poem

🎵 A tiny package, yet so grand,
Brings audio back to UEFI land,
Where UCM routes must have their say,
No silent speakers come this day! 🐰

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: adding alsa-ucm-conf package to uefi-common to enable PipeWire audio routing for SOF cards.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch uefi-common-add-alsa-ucm-conf

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