[hnfong]

I'm pretty sure your legal analysis here is overly-simplistic, but we don't need to get into that.

Going back to the original topic, if somebody is trying to release open source drivers for HDMI (or a protocol compatible with HDMI), obviously trademark infringement is a possibility since both are in the exact same business. So even if you're right (which I don't think so), your argument doesn't apply.

[echoangle]

Being in the same business does not make it trademark infringement. Ubuntu could also advertise "This OS can run software for Windows by using WINE" without infringing on Microsoft's trademark, because they aren't acting under the trademark. Trademarks exist so you can't sell your product under the established name of another company and profit from their reputation or ruin it by selling bad products. Just mentioning the name to state a fact is not forbidden. Just writing a driver and distributing it with the claim "HDMI-compatible" is not trademark infringement. They problem in OP's article is that AMD has a contract with the HDMI Forum.

[hnfong]

My comment does not contradict anything you say here.

[echoangle]

Do you think it would be trademark infringement if I code a HDMI driver and then publish it on GitHub with the description "This is a HDMI-Compatible driver"?