As you already know, Ubuntu 22.04 LTS “Jammy Jellyfish” came out very recently, causing a stir among the Linux community. And here, just a few days after its release, came some surprising news. It has to do with NVIDIA and, more precisely, with their proprietary driver when used in the last LTS release of the distro.
We’ll briefly clarify that Ubuntu defaulted to using a GNOME Wayland session in recent years rather than X.Org when using Intel and Radeon drivers. At the same time, with NVDIA’s drivers, the default session stuck to X.Org.
However, in the last month, Canonical decided that the GNOME session should default to Wayland in Ubuntu 22.04 when using the NVIDIA proprietary driver. The primary and admittedly sensible argument for this decision is that the latest versions of the NVIDIA proprietary driver support GBM, which puts it in a great position to work seamlessly with Wayland.
To clarify, Generic Buffer Management (GBM) is an API that provides a mechanism for allocating buffers for graphics rendering tied to Mesa.
Unfortunately, a few days ago, just after the official announcement of Ubuntu 22.04, NVIDIA requested Canonical to bring back X.Org as the default GNOME session in Ubuntu 22.04 LTS when using their proprietary driver.
If you’re wondering what’s causing this, it’s a last-minute bug, rendering the incorrect frame, which appears visually as a doubling of moving objects or high-frequency judder.
As a result, the GNOME Display Manager (GDM) package in Ubuntu 22.04 has been updated so that NVIDIA-only systems now use the GNOME X.Org session by default. So all NVIDIA-only systems will receive the updated version of the DGM package as part of their regular updates.
The updated gdm3 package (version 42.0-1ubuntu7) was uploaded on Thursday and is not included in the Ubuntu 22.04 LTS release image.
However, the Wayland session option will be available on the login screen for those Ubuntu users who insist on using it. In addition, Wayland will still be the default GNOME session in hybrid graphics systems with a mix of NVIDIA and Intel/AMD GPUs.
At the moment, there is confirmation from NVIDIA that they are working to fix the problem.
We have been trying to figure out a solution for a while; it’s proven to be a rather difficult problem. At the moment, we don’t have support for implicit buffer synchronization like the open-source stack does. That would probably be the proper fix, and we are working on some of the underlying infrastructures that it would require.
So, by default, NVIDIA on Ubuntu 22.04 LTS now uses the X.Org session again. Still, we hope this issue will soon be fixed, and the Ubuntu users who use an NVIDIA GPU will again enjoy the benefits that Wayland provides.
