Use mainline to easily upgrade your kernel

When I installed Xubuntu 22.04 I was shocked to see that Bluetooth wasn’t working. One mainline kernel install and everything worked like a dream.

Use mainline to easily upgrade your kernel

When I installed Xubuntu 22.04 I was shocked to see that Bluetooth wasn’t working. I’ve got a pretty standard and well-supported Bluetooth chipset, Intel Wireless-AC 3168 Bluetooth, so this threw me for a loop.

After blaming and then apologizing to Blueman, I found a hint on the Arch Linux forum. The kernel version on 22.04, 5.15.0.18.18, is currently broken with several Intel Bluetooth chipsets. There were reports in that same thread that the issue was resolved in 5.15.4, so I set out to upgrade my kernel… something I haven’t had to do in a really long time.

Upgrading my kernel

The good news is, upgrading your kernel no longer requires that you compile it yourself. Did I mention that it’s been a really long time since I’ve had to do this? After searching for a bit, I came across suggestions to use a utility called Ukuu (the “Ubuntu Kernel Update Utility”). However, this project is no longer free. Instead, you should now use a project called mainline.

Fair warning now… installing alternative kernels could leave your system in a worse state than you started. Just like the version currently available in Xubuntu 22.04, kernel updates can have regressions and will be less tested than those you find in the standard Ubuntu repositories. You have been warned!

Installing mainline

To easily install the latest version of mainline and stay up-to-date, use the cappelikan PPA. Fire up a terminal and enter the following commands:

sudo add-apt-repository ppa:cappelikan/ppa
sudo apt update
sudo apt install mainline

Once installed, you will find Ubuntu Mainline Kernel Installer in your application menu.

Using mainline

The application interface is pretty straight-forward. Select a kernel version, click Install, and it will be installed!

From here, everything is easy. Select your desired kernel version (I opted for 5.15.24) and click Install. The kernel was installed and my NVIDIA kernel modules were installed alongside it. Upon rebooting, everything, including my Bluetooth, was functional!

Your mileage may vary, but for me, this was the last thing I needed to be running at 100% with Xubuntu 22.04. Here’s hoping this helps somebody else with unexplainable Bluetooth issues. 😉