Comment 30 for bug 1915117

For the sake of testing, I checked on the latest Impish daily image, with kernel 5.11.0-18-generic. Same problem. dmesg attached. Alsa and PulseAudio don't detect any sound card, even though in dmesg we can see:

$ sudo dmesg | grep -i snd
[ 26.169850] snd_hda_intel 0000:00:1f.3: DSP detected with PCI class/subclass/prog-if info 0x040100
[ 26.169858] snd_hda_intel 0000:00:1f.3: Digital mics found on Skylake+ platform, using SST driver

$ aplay -l
aplay: device_list:276: no soundcards found...
ubuntu@ubuntu:~$ pactl list cards
ubuntu@ubuntu:~$ pactl list sources
Source #0
 State: SUSPENDED
 Name: auto_null.monitor
 Description: Monitor of Dummy Output
 Driver: module-null-sink.c
 Sample Specification: s16le 2ch 44100Hz
 Channel Map: front-left,front-right
 Owner Module: 13
 Mute: no
 Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB
         balance 0.00
 Base Volume: 65536 / 100% / 0.00 dB
 Monitor of Sink: auto_null
 Latency: 0 usec, configured 0 usec
 Flags: DECIBEL_VOLUME LATENCY
 Properties:
  device.description = "Monitor of Dummy Output"
  device.class = "monitor"
  device.icon_name = "audio-input-microphone"
 Formats:
  pcm
ubuntu@ubuntu:~$ pactl list sinks
Sink #0
 State: SUSPENDED
 Name: auto_null
 Description: Dummy Output
 Driver: module-null-sink.c
 Sample Specification: s16le 2ch 44100Hz
 Channel Map: front-left,front-right
 Owner Module: 13
 Mute: no
 Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB
         balance 0.00
 Base Volume: 65536 / 100% / 0.00 dB
 Monitor Source: auto_null.monitor
 Latency: 0 usec, configured 0 usec
 Flags: DECIBEL_VOLUME LATENCY SET_FORMATS
 Properties:
  device.description = "Dummy Output"
  device.class = "abstract"
  device.icon_name = "audio-card"
 Formats:
  pcm