> You could certainly try and upstream an infringing implementation into the kernel, but no one would be able to distribute it in their products without a license.

Isn't that actually a pretty good workaround? Hardware vendor pays for the license, implements the standard, sells the hardware. Linux kernel has a compatible implementation, relying on the first sale doctrine to use the patent license that came with the hardware, and then you could run it on any hardware that has the port (and thereby the license). What's the problem?

> relying on the first sale doctrine to use the patent license that came with the hardware

First-sale doctrine protects against copyright or trademark infringement. You might be thinking of "patent exhaustion"[1], which is a mostly US-specific court doctrine that prevents patent holders from enforcing license terms against eventual purchasers of the patented invention. There is no "transitive law of patent licensing", so-to-speak.

In this case, it would still not protect Valve if they exercise each claim in the relevant patents by including both hardware and an unlicensed implementation of the software process. It would protect end users who purchased the licensed hardware and chose to independently install drivers which are not covered by the license.

It's murky if Valve would infringe by some DeCSS-like scheme whereby they direct users to install a third-party HDMI 2.1 driver implementation on first boot, but I don't think they would risk their existing HDMI license by doing so.

1: https://en.wikipedia.org/wiki/Exhaustion_doctrine_under_U.S....