After Upgrading to Ubuntu Focal (20.04) unfortunately the sound on my Lenove Yogabook 11e stopped working.
More concrete it didn't show any of the two sound devices I found by cat /proc/asound/cards in the shell, but an
Dummy Device Only
It took me some searches to find the following sources that let me fix the problem and get back a working sound system:
<cli> echo „options snd-hda-intel dmic_detect=0“ | sudo tee -a /etc/modprobe.d/alsa-base.conf
echo „blacklist snd_soc_skl“ | sudo tee -a /etc/modprobe.d/blacklist.conf
</cli>
<cli> pulseaudio -k && sudo alsa force-reload </cli>
Update
Kernel: Linux 5.4.0-52-generic #57-Ubuntu SMP Thu Oct 15 10:57:00 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
With this Kernel it suddenly became necessary to
- undo the changes in alsa-base.conf (e.g. by commenting out the above mentioned lines again)
- reboot device
- but still
<cli> pulseaudio -k && sudo alsa force-reload </cli>
once after a fresh reboot.
Linux ThinkPad-Yoga 5.4.0-53-generic #59-Ubuntu SMP Wed Oct 21 09:38:44 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
:eyeroll: Six days later the commented lines have to be uncommented again. Just because ....
If you have opened an app like firefox ...
... before you reload alsa you must do
<cli>sudo killall timidity</cli>
It seems that this line actually is sufficient to fix the problem! Just try it if you just have a dummy device.
<markdown>Either you have to redo </markdown>
<cli>pulseaudio -k && sudo alsa force-reload</cli>
<markdown>again or the soundcard will appear immediately.
</markdown>
homer