AMD has had issues with their HDMI drivers on Linux. The company's designers suggested to the HDMI Forum that the drivers could be released as open-source drivers, but this was not acceptable to the organization. Therefore, the problem with the latest HDMI features remains unresolved.
This concerns the new HDMI 2.1 standard. For example, it features Fixed Rate Link (FRL) signaling, allowing uncompressed video to be passed through the connection at over 4K60 resolution and speed.
AMD's open-source HDMI 2.1 driver for Linux cannot utilize the new standard's FRL functionality, which also forms the basis for Variable Refresh Rate (VRR). As a result, Linux users with AMD processors cannot enjoy these features, which are important for example for people how play videogames.
According to the organization, releasing the driver as open-source would make the entire standard publicly available. However, the rules of participation in HDMI standardization prevent AMD from releasing the technology it has developed for the interface standard.
AMD regrets the organization's stance but cannot do anything about the situation. However, the company says that fortunately, DisplayPort connections are also available on the edges of the graphics cards. AMD's open-source driver does support a DP-HDMI 2.1 adapter.
In terms of performance, the latest HDMI and DisplayPort connections are largely comparable. HDMI is, of course, more widely used, especially in 
televisions.
