GNOME's Mutter Working On "Max BPC" Handling To Deal With Monitor Issues

GNOME developers are working on supporting the Linux KMS "Max BPC" connector property that is supported by some of the Direct Rendering Manager drivers for limiting the maximum bits per color permitted. In turn properly supporting this setting can take care of monitor issues seen on some systems where the monitor may randomly flicker or have other issues unless otherwise lowering the refresh rate or resolution.

Canonical's lead GNOME contributor, Daniel van Vugt, has been working on the Max BPC connector property support the past several weeks for GNOME. By having GNOME's Mutter support this on X.Org and Wayland, it can be used for lowering display bandwidth requirements in cases where the system can't properly drive particular displays out of the box. There are various bug reports over displays with the Linux desktop intermittently flickering or other display bandwidth related issues. Lowering the color depth is one option to avoid the bandwidth problems as an alternative to lowering the resolution or refresh rate (or making hardware changes like switching from HDMI to USB-C or DisplayPort). On the opposite end, the max BPC connector support can be used for increasing the displayed color depth for the Linux DRM/KMS drivers if it defaults to a lower value than desired.

The GNOME "Max BPC" propery support should help in dealing with some annoying Linux monitor issues under some conditions.

The Max BPC connector property for DRM/KMS drivers has been around for a few years and supported by the common open-source drivers.

Daniel van Vugt is working on this after hitting a display issue himself with a new monitor and also aiming to address various Ubuntu bug reports around display issues (like this bug with Intel graphics) that could be alleviated with this "max BPC" property support. The upstream Mutter work can be tracked via this work-in-progress MR. It also looks like he hopes to be able to carry these patches back-ported to stable branches to be able to ship this for existing Ubuntu users.