As I wrote previously, I’m suspecting a Linux kernel bug somewhere between versions 5.13.0-22 and 5.13.0-23, in the Ubuntu kernels. I wanted to know if the issue only surfaced in Ubuntu-flavored kernels, or also in the upstream (mainline) kernels from kernel.org.
There is an Ubuntu Mainline PPA with all the upstream kernels, but I found it a bit too opaque to use. Fortunately I found the Ubuntu Mainline Kernel Installer (UMKI), a tool for installing the latest Linux kernels on Ubuntu-based distributions.
The UMKI is pretty straightforward. It fetches a list of kernels from the Ubuntu Mainline PPA and a GUI displays available and installed kernels, regardless of how they were installed. It installs the kernel, headers and modules. There is also a CLI client.
To install the UMKI:
sudo add-apt-repository ppa:cappelikan/ppa
sudo apt update
sudo apt install mainlineWith that out of the way, there’s the matter of deciding which kernels to try. The “interesting” Ubuntu kernels are 5.13.0-22 and 5.13.0-23, so the mainline kernels I definitely want to test, are around those versions. That means 5.13.0 and 5.13.1. I also want to try the latest 5.13.x kernel, so that’s 5.13.19, and the most recent stable kernel, 5.16.11 (as of 2022-03-01).
To summarize, I have tested these mainline kernels:
5.13.05.13.15.13.195.16.11
The result (after several reboots)? With all of them, my keyboard and mouse worked without a hitch. That means the issue most likely doesn’t occur in (stable) mainline kernels, only in kernels with additional patches from Ubuntu.
Up next: compiling kernels from source.
Lasciate ogne speranza, voi ch’intrate.
Dante Alighieri