Lenovo Yoga C940

Still working on installation, wiki will come soon.

Hardware Lenovo Yoga C940
on linux-5.7.5 kernel

Graphics
Works using x11-drivers/xf86-video-intel with VIDEO_CARDS="intel i965 iris".

See Intel.

Display
Worked out-of-the box in X.

bluetooth
Could pair with a bluetooth headset

Thermal shutdowns
It seems that one temperature sensor is not taken into account properly when throttling the CPU. This leads to frequent thermal shutdowns when under high load, especially when the battery is being charged.

Solution for now:


 * 1) Install  and add it to the default runlevel
 * 2) Put the following custom configuration into

This is the configuration provided by the firmware plus an entry for SEN4 which is responsible for most of the shutdowns on my system.

HiDPI
Set global scaling in your desktop configuration. For KDE this can be found right below the display configuration.

With X it was impossible to have different scaling factors per monitor, which makes external monitors hard to use unless they have similar resolution.

I have a somewhat working setup now with Plasma 5.19 / KDE 20.04 and wayland.

Screen rotation
Seems to be unstable with Plasma 5.19.

Sounds
Currently there seems to be no way to get sound to work properly. Some people had success with getting at least the sound bar to work. I didn’t

As of February 2021 there is a patched bios image (customized version 57 provided by Lenovo staff) that fixes the issue. Check out kernel bug comments and Lenovo forum thread for details and instructions. After that bios upgrade audio has been confrimed to work on recent Gentoo using 5.10.10+ kernel version (this author used 5.10.10 and no special settings).

Automatic screen rotation
Didn’t look into it yet.