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:
*
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
*
pulseaudio -k && sudo alsa force-reload
## 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
pulseaudio -k && sudo alsa force-reload
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
sudo killall timidity
**It seems that this line actually is sufficient to fix the problem!**
Just try it if you just have a dummy device.
Either you have to redo
pulseaudio -k && sudo alsa force-reload
again or the soundcard will appear immediately.