USB-Audio: ALC4082 - add MSI MEG X870E GODLIKE (0db0:e5c3)

USB-Audio: ALC4082 - add MSI MEG X870E GODLIKE (0db0:e5c3)

[GitHub pull_request - opened]

alsa-project/alsa-ucm-conf pull request #789 was opened from Tomcatt:

## Summary

The MSI MEG X870E GODLIKE (MS-7E48) uses the Realtek ALC4082 codec
presented as a USB Audio class device (USB ID 0db0:e5c3).

Two fixes:

**1. `ucm2/USB-Audio/USB-Audio.conf`** — add `e5c3` to the ALC4080
profile match so the device is recognised and routed to the correct
profile.

**2. `ucm2/USB-Audio/Realtek/ALC4080-HiFi.conf`** — add `e5c3` to the
`spdif_dev2` condition. On this board the optical S/PDIF output is on
ALSA sub-device 2 (Interface 6, Endpoint 8 OUT, stereo, up to 192 kHz)
rather than the default sub-device 3. Without this fix the
`iec958-stereo` ACP profile produces valid S/PDIF framing — the
receiver locks on and clicks — but the PCM audio payload is silent.
Routing to sub-device 2 confirmed working.

## Hardware

- Board: MSI MEG X870E GODLIKE (MS-7E48)
- USB device: `0db0:e5c3 Micro Star International USB Audio`
- Kernel: 7.0.12 (CachyOS), ALSA `snd-usb-audio`
- `lsusb`: `Bus 003 Device 005: ID 0db0:e5c3 Micro Star International USB Audio`

## Verification

```
$ aplay -l | grep -A1 'card 4'
card 4: Audio [USB Audio], device 0: USB Audio [USB Audio]
card 4: Audio [USB Audio], device 1: USB Audio [USB Audio #1]
card 4: Audio [USB Audio], device 2: USB Audio [USB Audio #2]  ← optical S/PDIF
card 4: Audio [USB Audio], device 3: USB Audio [USB Audio #3]

$ paplay --device=alsa_output.usb-Generic_USB_Audio-00.pro-output-2 \
    /usr/share/sounds/alsa/Front_Center.wav
# Audio confirmed received by amplifier via optical TOSLINK
```

Without the `spdif_dev2` fix, `hw:Audio,3` produces a valid S/PDIF
carrier (receiver relay clicks) but silent PCM. With the fix,
`hw:Audio,2` delivers audio correctly.

Request URL   : https://github.com/alsa-project/alsa-ucm-conf/pull/789
Patch URL     : https://github.com/alsa-project/alsa-ucm-conf/pull/789.patch
Repository URL: https://github.com/alsa-project/alsa-ucm-conf