HDMI Forum rejects AMD's HDMI 2.1 open-source driver

Original Article ↗ Hacker News Discussion ↗

HDMI Forum’s refusal to let AMD release an open‑source HDMI 2.1 driver has reignited criticism of HDMI’s closed, royalty‑bearing standard and its reliance on NDAs. Commenters argue this blocks Linux and open drivers from fully supporting modern TVs and high‑refresh 4K displays, and see it as protectionism that could invite antitrust or regulatory scrutiny. Many advocate shifting toward DisplayPort and USB‑C, which are viewed as technically superior and more open, though HDMI’s ubiquity in TVs and home theater gear makes such a transition difficult.

HDMI Forum decision and legal/IP context

  • HDMI 2.1 specs were made non-public in 2021; access requires NDAs and licensing via HDMI Forum/HDMI LA.
  • AMD accessed the spec under NDA, so releasing an open-source driver that embeds spec “secrets” would violate that NDA.
  • Some argue clean-room reverse engineering would be legal, but AMD chose the NDA path, which now blocks open code.
  • There is debate over whether the sensitive material is trade secrets vs copyrightable content and what that implies for leaks or third‑party implementations.

Open-source, Linux, and AMD implications

  • Linux users lose HDMI 2.1 features (e.g., 4K@120Hz, VRR) on AMD’s otherwise open drivers, while proprietary drivers or other vendors can ship full support.
  • Suggestions that AMD should “leak” the driver face pushback: it would be illegal, couldn’t be maintained by AMD, likely couldn’t go in mainline kernels, and would be fragile out‑of‑tree.
  • Some propose fallback drivers or user-installed modules, but legality and distro support are questioned.

DisplayPort vs HDMI: technology and ecosystem

  • Many see HDMI as technically inferior and encumbered (royalties, HDCP, ARC/CEC complexity, unreliability, long handshake delays).
  • DisplayPort is viewed as cleaner and packet‑based, with features like MST and better alignment with USB‑C Alt Mode; it effectively underlies many USB‑C and internal eDP links already.
  • Counterpoints: TVs and many monitors lack DP; HDMI’s ARC/eARC and CEC remain important for TV/soundbar/AVR setups. DP lacks a direct ARC equivalent and a return audio channel.
  • Bandwidth anecdotes: DP1.4 can be limiting for high-refresh HDR; HDMI 2.1 sometimes wins on raw bandwidth unless DP2.0 and/or DSC are available.
  • DP↔HDMI adapters work but are asymmetric and often limited in supported modes.

Government, standards, and market power

  • Some call for regulation: mandating open standards or treating HDMI Forum as a cartel/gatekeeper (EU DMA, antitrust angles).
  • Others blame IP law (patents, DMCA, trade secrets) for enabling such control; there’s a long side‑discussion on monopolies, “free markets,” and whether IP should be curtailed or abolished.
  • A few suggest consumer pressure: avoid proprietary standards where possible, favor DP/USB‑C, and let HDMI wither in the long run.

User experiences and workarounds

  • Users report practical issues: TVs as monitors limited to HDMI, difficulty achieving advertised 4K120/144Hz, ARC quirks, and EDID/handshake bugs.
  • Workarounds mentioned include using DP‑to‑HDMI 2.1 active adapters, preferring DP on PCs, and relying on USB‑C/DP Alt Mode where available.