Thanks Vic. I see from logs that the HDA codec is an ALC 233, which happens to be the same Realtek HDA codec I have in my Lenovo Thinkcentre machine that's running UC20 20200529.3. Unfortunately my Thinkcentre doesn't have any HDMI ports, but I was able to send sound through one of the displayports.
It's interesting to note that, despite being the same kernel and same codec, the log messages seem different (for instance, I didn't see SOF messages in your logs. Here I see something like: Jun 01 20:06:33 stormfly kernel: sof-audio-pci 0000:00:1f.3: DSP detected with PCI class/subclass/prog-if info 0x040380 (...) Jun 01 20:06:33 stormfly kernel: sof-audio-pci 0000:00:1f.3: hda codecs found, mask 5 Jun 01 20:06:33 stormfly kernel: sof-audio-pci 0000:00:1f.3: using HDA machine driver skl_hda_dsp_generic now To send audio to my displayport, I used something like: # aplay -D hw:sofhdadsp,5 -f S16_LE -c 2 /bin/ls (or, to play music instead of noise, mpg123-cm.mpg123 -o alsa -a hw:sofhdasp,5 test.mp3) In amixer, my device is 'PGA9.0 9 Master'. I wonder if the IEC958 in your mixer settings could be a digital audio output such as a S/PDIF port or something similar? Could you post the output of # aplay -l and # aplay -L so we can see the all the available cards/devices? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1879630 Title: No sound output from HDMI audio To manage notifications about this bug go to: https://bugs.launchpad.net/snapd/+bug/1879630/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs