Bug#1111180: Audio: Intel Cannon Lake PCH cAVS not detected on HP EliteDesk 800 G5

[Evka <evka.evans@gmail.com>]

Package: linux
Severity: important

Dear Maintainers,

The integrated audio device on my HP EliteDesk 800 G5 Desktop Mini is not detected by the kernel in Debian Trixie. Consequently, `aplay -l` finds no sound cards, and the system defaults to a "Dummy Output".

System information tools confirm the kernel is not attaching a driver to the hardware (`driver: N/A`).

This appears to be a kernel driver bug/regression with the `snd_sof_pci_intel_cnl` module for this specific hardware, as exhaustive troubleshooting has ruled out all common configuration and setup issues.

**System Summary:**
* **Machine:** HP EliteDesk 800 G5 Desktop Mini
* **CPU:** Intel Core i5-9500 (Coffee Lake)
* **Audio Device:** Intel Cannon Lake PCH cAVS (HP Subsystem)
* **Kernel:** 6.12.41+deb13-amd64
* **Distro:** Debian GNU/Linux 13 (trixie)
* **Desktop:** Cinnamon 6.4.10

**Hardware Details (from `lspci`):**
00:1f.3 Audio device [0403]: Intel Corporation Cannon Lake PCH cAVS [8086:a348] (rev 10)
    Subsystem: Hewlett-Packard Company Device [103c:8594]

**Summary of Diagnostic Steps Performed:**

This is not a user configuration error. The following steps have been meticulously performed and have failed to resolve the issue:

1.  **Firmware:** Confirmed the correct `firmware-sof-signed` and `firmware-intel-sound` packages are installed. This was necessary after discovering the `sof-firmware` package has been renamed in Trixie.

2.  **Driver Conflict:** Identified and resolved a conflict between the legacy `snd_hda_intel` driver and the modern `snd_sof` driver. The `snd_hda_intel` module has been successfully blacklisted.

3.  **Kernel Parameter:** Booted with the kernel parameter `snd_intel_dspcfg.dsp_driver=1` added to the kernel command line. This had no effect; the hardware was still not detected.

4.  **BIOS/UEFI:** Confirmed that the "Onboard Audio" device is "Enabled" in the system BIOS/UEFI settings (HP R21 Ver. 02.22.00).

5.  **ALSA Configuration:** Confirmed there are no custom user (`~/.asoundrc`) or system-wide (`/etc/modprobe.d/alsa-base.conf`) ALSA configuration files causing interference.

6.  **Package Manager / Mirror:** Ruled out issues with the `apt` package manager by completely rebuilding the cache and switching to a primary Debian mirror.

Despite all of the above, `aplay -l` remains empty. This strongly suggests a bug within the kernel's SOF driver stack for this specific hardware combination.

Thank you for your time and work on the Debian kernel. Please let me know if any further information or testing is required.