Mainline kernel 6.15.4: snd_soc_intel_soundwire_sof_mach.ko missing despite CONFIG enabled

[Jan Kranefeld]

On Ubuntu Mainline Kernel 6.15.4-061504-generic, the kernel configuration contains:

  CONFIG_SND_SOC_INTEL_SOUNDWIRE_SOF_MACH=m

However, the compiled kernel module `snd_soc_intel_soundwire_sof_mach.ko` is missing from the installed package:

  linux-modules-6.15.4-061504-generic

This module is required for audio functionality on Intel platforms using SOF + SoundWire (e.g. Lunar Lake, Meteor Lake), including:

  - Intel Lunar Lake SoC
  - CS42L43/CS35L56 codec combinations
  - ThinkPad X9 Gen 1 and similar hardware

Without this module, affected systems have no audio devices except "Dummy Output".

---

**Expected behavior**:
- The module should be included in the package and available under:
  /lib/modules/6.15.4-061504-generic/kernel/sound/soc/intel/boards/

**Actual behavior**:
- The module is missing.
- `modinfo` fails with:

  modinfo: ERROR: Module snd_soc_intel_soundwire_sof_mach not found.

---

**Steps to reproduce**:
1. Install 6.15.4 from https://kernel.ubuntu.com/mainline/v6.15.4/
2. Reboot into kernel 6.15.4-061504-generic
3. Run:

     modinfo snd_soc_intel_soundwire_sof_mach

---

**Impact**:
This module is required for proper SOF SoundWire audio support on modern Intel hardware. Several distributions (Fedora, Arch) include this module by default. Without it, mainline kernels are incomplete for current-generation laptops and embedded devices.

Please include the compiled module `snd_soc_intel_soundwire_sof_mach.ko` in future linux-modules-* packages when CONFIG is set to `=m`.

Tested system:

  Kernel: 6.15.4-061504-generic
  GCC: 14.2.0
  Arch: amd64
  Device: Lenovo ThinkPad X9 14 Gen 1 (Intel Lunar Lake)

[Jan Kranefeld (kranefeld)]

journalctl -b | grep -E "sof[-_]|cs(35|42)l"
Jul 05 19:44:40 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: enabling device (0004 -> 0006)
Jul 05 19:44:40 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: DSP detected with PCI class/subclass/prog-if 0x040100
Jul 05 19:44:40 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: bound 0000:00:02.0 (ops intel_audio_component_bind_ops [xe])
Jul 05 19:44:40 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: use msi interrupt mode
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: hda codecs found, mask 4
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: NHLT device BT(0) detected, ssp_mask 0x4
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: BT link detected in NHLT tables: 0x4
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: DMICs detected in NHLT tables: 2
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: Firmware paths/files for ipc type 1:
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: Firmware file: intel/sof-ipc4/lnl/sof-lnl.ri
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: Firmware lib path: intel/sof-ipc4-lib/lnl
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: Topology file: intel/sof-ipc4-tplg/sof-lnl-cs42l43-l0-cs35l56-l3-2ch.tplg
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: sof-audio-pci-intel-lnl 0000:00:1f.3: Loaded firmware library: ADSPFW, version: 2.12.0.1
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs42l43 sdw:0:0:01fa:4243:01: supply vdd-p not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs42l43 sdw:0:0:01fa:4243:01: supply vdd-d not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs42l43 sdw:0:0:01fa:4243:01: supply vdd-a not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs42l43 sdw:0:0:01fa:4243:01: supply vdd-io not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs42l43 sdw:0:0:01fa:4243:01: supply vdd-cp not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs35l56 sdw:0:3:01fa:3556:01:0: supply VDD_P not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs35l56 sdw:0:3:01fa:3556:01:0: supply VDD_IO not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs35l56 sdw:0:3:01fa:3556:01:0: supply VDD_A not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs42l43 sdw:0:0:01fa:4243:01: devid: 0x042a43, rev: 0xa1, otp: 0x03
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs35l56 sdw:0:3:01fa:3556:01:0: Cirrus Logic CS35L56 Rev B0 OTP3 fw:3.4.4 (patched=0)
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs35l56 sdw:0:3:01fa:3556:01:0: Slave 2 state check1: UNATTACHED, status was 1
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel: cs35l56 sdw:0:3:01fa:3556:01:1: supply VDD_P not found, using dummy regulator
Jul 05 19:44:41 ThinkPad-X9-14-Gen-1 kernel...

[Massimiliano Pellizzer (mpellizzer)]

Thanks for reporting the bug,
As reported in https://kernel.ubuntu.com/mainline/?C=N;O=D, mainline kernels are meant to be used for debugging purposes only. We will not provide any support for those kernels.

[Jan Kranefeld (kranefeld)]

Thanks for your reply, will this module be included in the upcoming kernel 6.16 stable release? Or to ask more precisely: How would I report this to be included in it?

[Juerg Haefliger (juergh)]

The module is name snd-soc-sof-sdw.

[Jan Kranefeld (kranefeld)]

Thanks for the reply, this seems to be true. sudo modprobe snd_soc_sof_sdw works and SOF-DSP and SoundWire start without error. Now there only seem to be issues with the cs42l43 firmware. Thank you very much!