GNU/Linux Desktop Survival Guide
by Graham Williams
20201011 Yoga is a Lenovo ThinkPad X1 Yoga 4th Gen. See Section 36.1 for details.
Audio Fail on Kernel Upgrade 20200322 An upgrade of the kernel on Ubuntu 19.10 from 5.3.0-40 to 5.3.0-42 (and then 5.3.0-45) resulted in the audio (speaker, hub headphones, and HDMI monitor) not working. Bluetooth headphones remained working, including microphone. Computer microphone was not working irrespective. Under kernel 5.3.0-40 /proc/asound/cards had two cards listed (PCH and USB). Research suggested the issue is with the SND_HDA_INTEL_DETECT_DMIC configuration which was enabled in the kernel updates. Disabling it fixed the issue and can be done by adding a kernel option to GRUB in /etc/default/grub (see Section 12.1):
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash snd_hda_intel.dmic_detect=0"
$ sudo update-grub
Microphone Fail 20200225 The four built-in
microphones along the top of the screen were not working on the
default Ubuntu 19.10 install. An external microphone is required for
voice communications. After upgrading to Ubuntu 20.04 with the new
kernel support of SOF the microphones were working for the first time.
The MIC is KIOXIA Corporation supported in kernel module
sof-skl_hda_card, same as in the Lenovo ThinkPad X1 Carbon 7th
Key Mappings The keyboard has the Fn and Ctrl keys swapped but can be changed in the BIOS. The Function keys (F1-F12) can also be set to either issue the Function or the icon action by default with my typical preference being to issue the Function rather than the Action, and so perform the Action by pressing the Fn key (which might be swapped with Ctrl). The behaviour can be swapped in the BIOS.
Fingerprint Reader The fingerprint reader is not functional. Ubuntu does not yet have mature support out-of-the-box for fingerprint readers. From https://launchpad.net/~3v1n0/+archive/ubuntu/libfprint-vfs0090
# Initialize the device $ sudo snap install validity-sensors-tools $ sudo snap connect validity-sensors-tools:raw-usb $ sudo snap connect validity-sensors-tools:hardware-observe $ sudo validity-sensors-tools.initializer Unable to access to USB devices validity-sensors-tools is installed as a snap. To allow it to function correctly you may need to run: sudo snap connect validity-sensors-tools:raw-usb sudo snap connect validity-sensors-tools:hardware-observe
It may be that it is a Synaptic fingerprint reader that is not yet supported as in https://askubuntu.com/questions/1301592/how-to-turn-on-fingerprint-login-in-ubuntu-20-04