Upgrading Ubuntu 12.04 Desktop to the latest LTS enablement stack

The ATI Radeon HD 5770 graphics card on my main desktop computer died recently after months and months of noisy overheated operation (not a gamer myself, the dust is the one to blame here). So I’ve recently upgraded the GPU and unfortunately, I also had to reinstall Ubuntu 12.04. After many failed attempts, I was unable to make the card work with the existing graphics stack (tried different versions of the AMD proprietary driver with no luck). Fortunately I have a separate /home partition, so reinstalling Ubuntu is not that much of a pain.

So I decided to re-install the system and I downloaded a fresh 12.04 image from Ubuntu’s website. Soon after the installation completed, I noticed that the new Ubuntu image came with an updated Linux kernel, one from the 3.5 series instead of the normal 3.2 that I was used to see on my old Ubuntu 12.04 installation. I doubled check with my laptop’s 12.04 install, and effectively, there I can see a 3.2 kernel.

It seems that Ubuntu is shipping its newer Ubuntu Desktop images with updated Linux kernel and X stacks, what they call the “LTS Hardware Enablement Stack“. This is happening since the 12.04.2 point release. Point releases 0 and 1 shipped with a 3.2 kernel. So if you have an old 12.04 LTS installation , any upgrades applied via the update-manager or apt-get will only ever install kernels from the 3.2 series.

It turns out that this is a policy that they plan to continue with in future 12.04 point releases, where the kernel and X stack will be aligned to the latest Ubuntu available at the time.

However, in order to get these newer kernels you either need to install a system from a 12.04.2+ image or alternatively, opt-in by manually running the following command that will upgrade your installation to the quantal enablement stack (the latest at the time of writing).

$ sudo apt-get install linux-generic-lts-quantal xserver-xorg-lts-quantal

In case anyone wonder, the fresh Ubuntu 12.04 installation fixed the problem I was experiencing with the graphics. But to be completely honest, I still don’t know exactly why it did.