[BUG/Feature Request] Dell XPS 15 9560 (Kaby Lake): Internal DMIC missing, AVS crashes, SOF unsupported. Seeking guidance to write machine driver.

[mattia-semprini]

Hi everyone,

I am trying to get the internal digital microphone (DMIC) working on my Dell XPS 15 9560. I am currently running Ubuntu 24.04 with the 6.8.0-oem kernel. I know that Kaby Lake DMIC support is in a transitional phase, and I am willing to write, patch, or test the required machine driver/topology if someone can point me in the right direction.

Here is the current state of the audio stack on this machine based on the DSP driver used:

1. Legacy snd_hda_intel (dsp_driver=1) - Currently in use

• Status: Speakers work perfectly. Headset mic/jack works perfectly (when using options snd-hda-intel model=dell-headset-multi).
• Issue: Internal DMIC is completely invisible. Overriding pins via hdajackretask (e.g., Node 0x12) exposes a mic in the OS, but it captures zero audio (stays MM), confirming it's a DMIC connected directly to the Intel DSP, not routed through the Realtek ALC3266 codec.

2. AVS Driver snd_soc_avs (Default in Ubuntu 6.8 OEM)

• Status: Completely breaks the audio stack. Neither speakers nor internal mic work. No audio devices are found. I currently have to blacklist snd_soc_avs to get audio output back.

3. SOF Driver (snd_intel_dspcfg dsp_driver=3)

• Status: Fails to load entirely. snd_sof modules are not loaded by the kernel. Even when forcing options snd-sof-intel-hda-common ipc_type=1, the driver refuses to bind to this specific Kaby Lake platform.

Hardware Info:

• Laptop: Dell XPS 15 9560
• CPU: Intel Core i7 (7th Gen Kaby Lake)
• Audio Controller (from lspci): Intel CM238 HD Audio Controller [8086:a171] (Subsystem: Dell [1028:07be])
• Audio Codec (from proc): Realtek ALC3266 & Intel Kabylake HDMI
• OS: Ubuntu 24.04 LTS
• Kernel: 6.8.0-oem

How can I help?
Since I want to fix this at the kernel/ASoC level, could you point me to the right machine driver to modify or create (e.g., in sound/soc/intel/boards/)? Why does AVS crash on this specific board?

(I will attach the full alsa-info.txt generated with the legacy driver active to this thread).

I am ready to provide full acpidump / DSDT tables and compile test kernels. Thanks in advance for any guidance!

alsa-info.txt