I bought a Lenovo Ideapad C340 laptop (14 inches) recently and have been having problems with the screen resolution. This laptop has an AMD Ryzen CPU and a Radeon Vega 10 APU. I tried Ubuntu 20.04 beta, Ubuntu Mate 20.04 beta and Ubuntu 18.04.04. All are running Linux 5.+ kernels that support the amdgpu driver. The behaviour was more or less the same.
The core of the matter is that the graphics card supports only a handful of screen resolutions, and not 1378x768, which is the most user-friendly resolution at this screen size. Here is what is supported according to xrandr (Windows also sees the same ones)
~$ xrandr
Screen 0: minimum 320 x 200, current 3072 x 1728, maximum 16384 x 16384
eDP connected primary 3072x1728+0+0 (normal left inverted right x axis y axis) 309mm x 173mm
1920x1080 60.01*+
1680x1050 60.01
1280x1024 60.01
1440x900 60.01
1280x800 60.01
1280x720 60.01
1024x768 60.01
800x600 60.01
640x480 60.01
I've read online that fractional scaling at a higher resolution might also work (or scaling fonts by changing dpi), but lets face it, this feature is at its current state quite horrible and does not work well. (font scaling is particularly bad, fractional scaling on Ubuntu 20.04 was bearable, but was still a major downgrade from my 6-year old laptop running Ubuntu 16 at 1368x768)
I tried adding a custom resolution to xrandr using this guide (link), but that only resulted in a black screen.
Any suggestions to what can be done? Is it hopeless with the graphics card and should I just stay away fro AMD/Radeon in the future?
