Comment 27 for bug 1864061

Thanks -- looks like it's working!

For anyone else with this problem, I enabled proposed (as found in https://wiki.ubuntu.com/Testing/EnableProposed), then ran apt install for:

linux-generic/eoan-proposed linux-headers-generic/eoan-proposed linux-image-generic/eoan-proposed linux-libc-dev/eoan-proposed linux-signed-generic/eoan-proposed linux-firmware libasound2

which ended up installing/upgrading:
  linux-headers-5.3.0-43 linux-headers-5.3.0-43-generic
  linux-image-5.3.0-43-generic linux-modules-5.3.0-43-generic
  linux-modules-extra-5.3.0-43-generic
  libasound2 libasound2-data libasound2-dev linux-firmware

I did NOT blacklist snd_soc_skl and snd_hda_intel in the /etc/modprobe.d/blacklist.conf since the comment said "after linux-image-5.3.0-43-generic is ready, the blacklist is not needed
anymore".

I kept the "options snd-hda-intel dmic_detect=0" that I had previously added to /etc/modprobe.d/alsa-base.conf, didn't try removing it.

Sound works again, pavucontrol sees the devices it saw in -40, amixer can control volume again.

It still doesn't see the built-microphone, but that's a different bug that I think is targeted for 20.04.