Screen Rotation and Fractional Scaling

[mynameisfiber]

Note for all, which may be useful for the README... to get screen rotation and fractional scaling to work you need to add the following to your kernel command line:

amdgpu.exp_hw_support=1

source: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1888088

[benoe77]

Is this for standard laptops or just for 2in1-s? I have fractional scaling working, and a new "Screen Lock" menu apeared (no force rotation menu in settings) after update to 5.11, but I only have standard form factor. I have Ubuntu 20.04.2 LTS

[jrandiny]

Hm I also have fractional scaling working on my machine (Ubuntu 20.04.2, Kernel 5.11)

[mynameisfiber]

Hrmm... I think the issue may be kernel version?

charm ~:$ uname -a
Linux charm 5.8.0-63-generic #71-Ubuntu SMP Tue Jul 13 15:59:12 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
charm ~:$ cat /etc/issue
Ubuntu 20.10 \n \l

Also, to be honest, I included fractional scaling in the title because that was another problem mentioned in the issue I linked to. I personally was experiencing problems with screen rotation. To test, run:

$ xrandr --output <the output monitor> --rotate left

Before making the modifications to my kernel line, this command completed without failure but the screen did not rotate.

[jrandiny]

$ xrandr --output <the output monitor> --rotate left works on my system (Ubuntu 20.04 Kernel 5.11). I think it's due to your kernel version

edit: Also works in kernel 5.8. Now i think it's related to the mesa version on Ubuntu 20.10

[mynameisfiber]

I have,

libgl1-mesa-dri/groovy-updates,now 20.2.6-0ubuntu0.20.10.1 amd64 [installed,automatic]
libgl1-mesa-glx/groovy-updates,now 20.2.6-0ubuntu0.20.10.1 amd64 [installed,automatic]

In the issue, that user had,

version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.8-0ubuntu1~20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A

[jrandiny]

My version

libgl1-mesa-dri/focal-updates,now 21.0.3-0ubuntu0.3~20.04.1 amd64 [installed,automatic]
libgl1-mesa-glx/focal-updates,now 21.0.3-0ubuntu0.3~20.04.1 amd64 [installed,automatic]

Maybe mesa 21 fixes the bug

[mynameisfiber]

Seems like a reasonable assumption. To be honest, I think the recommendation here isn't the above fix but rather to use ubuntu 20.04 when possible!