Nouveau Supporting HDMI 2.1 Won't Hopefully Be Too Challenging Thanks To NVIDIA Firmware

While there is a lot of frustration from the news last week of the HDMI Forum rejecting AMD's open-source HDMI 2.1 driver support plans, the open-source NVIDIA "Nouveau" driver won't hopefully have too challenging of an experience in enabling HDMI 2.1 functionality since much of the display handling there is left up to NVIDIA's (closed-source) firmware binaries.

Red Hat developer and longtime Nouveau contributor Karol Herbst posted on Mastodon after the AMD HDMI 2.1 news:

"Even though AMD might not be able to add support for HDMI 2.1, nouveau certainly will as Nvidia's open source driver _also_ supports HDMI 2.1 so there is no reason to believe that at least some drivers can't support HDMI 2.1

It's quite backwards, but apparently having all the logic inside firmware (like Nvidia does) will probably help us implementing support for HDMI 2.1 🙃"

NVIDIA's open-source kernel driver distributed out-of-tree as part of their Linux kernel driver package implements HDMI 2.1 functionality via the GSP firmware blobs and the Nouveau driver in the future could do so similarly. As of yet though that Nouveau feature integration has yet to happen for HDMI 2.1 functionality. With AMD though their HDMI 2.1 display functionality is programmed via their AMDGPU kernel driver rather than implementing it in firmware. AMD's current approach is better for open-source supporters rather than having more functionality within binary blobs.

We'll see in the future if AMD decides to move their HDMI logic to the firmware in order to be able to support HDMI 2.1 within their open-source driver. It's probably unlikely AMD will do this for current generation hardware given the work involved in shifting a lot of code to firmware, it not benefiting their larger Windows customer base in any substantive way, and all of the QA and related work involved, but we'll see in the future if this happens... Or if DisplayPort and other open standards can (hopefully) gain enough traction to diminish the concern over HDMI 2.1+ features under the AMD Linux graphics driver.