If you have an AMD RX 90xx or an AMD RX 90xx XT, you must use at least a 6.12 version kernel, a Mesa version 25.0 or newer, and install the necessary firmware.
Currently, none of these come with a Linux Mint 22 version ISO. You must upgrade all three in order to get graphics. Depending upon your motherboard/CPU, you may need newer versions of each of the three.
Install at least a 6.12 mainline kernel. Mainline kernels are unsigned. You will need to disable secure boot or sign them yourself. You can use Mainline – Another Tool to Install Latest Kernel in Ubuntu / Linux Mint to install the kernel.
-Upgrade the Mesa to at least version 25.0.
-Take a Timeshift snapshot.
-Install the kisak ppa (preferrable) or the oibaf ppa. Follow the instructions on the link. DO NOT USE ppa-purge to remove those if you change your mind. Use your Timeshift snapshot.
-Upgrade the amdgpu linux-firmware.
Upgrading the amdgpu linux-firmware
Especially in Linux Mint 21 versions, many bug fixes have been integrated into the amdgpu linux-firmware, but have not yet been added to the linux-firmware packages in LM21 versions. You can upgrade to the latest which have fixed problems with stuttering in web browsers, missing sound, and other problems.
Install the firmware. (Instructions updated 04 May 2025.)
-Take a Timeshift snapshot. If this change causes problems, a snapshot will be the best way to reverse the change.
-If you do not already have git installed, install it with:
sudo apt install git
-Navigate to your Downloads directory and right-click and select Open in Terminal and run the following:
git clone https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
This will create a /linux-firmware folder in /Downloads and populate it with all the firmware files. It will likely take some time to complete.
-Navigate to the ~/Downloads/linux-firmware/amdgpu/ folder and open a terminal in that directory and run the following lines one at a time.
sudo cp -u * /lib/firmware/amdgpu/
sudo update-initramfs -u -k all
-Reboot the computer.
-Slurp tea in a job well done.
https://forums.linuxmint.com/viewtopic.php?t=447543