Valve: HDMI Forum Continues to Block HDMI 2.1 for Linux

Original Article ↗ Hacker News Discussion ↗

Valve’s work on a new Linux-based Steam Machine has highlighted a long‑running conflict with the HDMI Forum, whose strict NDA and licensing terms effectively block an open‑source implementation of HDMI 2.1 features such as 4K120, HDR, and VRR on Linux. Commenters argue this illustrates broader problems with closed, patent‑encumbered “standards,” calling HDMI a rent‑seeking cartel and advocating a shift toward DisplayPort or USB‑C/USB4, which are seen as technically superior and less restrictive. Various workarounds like active DP‑to‑HDMI adapters, firmware blobs, and clean‑room reverse engineering are explored, but many see real progress as requiring either regulatory intervention or an industry move away from HDMI on consumer TVs.

HDMI 2.1 on Linux and Valve’s Problem

  • Core issue: HDMI Forum’s HDMI 2.1 license/NDAs forbid an open-source implementation, so AMD cannot upstream its working HDMI 2.1 support into Linux.
  • Closed drivers (e.g., firmware/user‑space blobs) can legally implement it; Nvidia already does this by moving sensitive parts into firmware.
  • Some suggest AMD/Valve could ship a tiny proprietary HDMI 2.1 blob or GSP‑style firmware, but that conflicts with Valve’s preference for fully open drivers.
  • Several commenters note that for the new Steam Machine’s GPU, HDMI 2.0 bandwidth is “good enough” for many games, but lack of VRR and full 4K120 HDR is still a major loss for living‑room gaming.

DisplayPort vs HDMI and the TV Ecosystem

  • Many argue DisplayPort is technically and economically superior (no per‑device royalties, earlier high‑refresh support, royalty‑free spec access via VESA fee), and want HDMI “gone.”
  • Frustration that TVs almost never ship with DisplayPort; some claim HDMI Forum discourages DP on TV SoCs, others say it’s mainly cost, SoC bandwidth limits, and negligible consumer demand.
  • Mass‑market inertia: consoles, streamers, and set‑top boxes are all HDMI‑only, so TV makers see little reason to expose DP even if they dislike HDMI royalties.
  • DP has its own issues (short passive cable runs, fiber cost), and CEC/eARC equivalents are weaker or fragmented.

Workarounds and Adapters

  • Common suggestion: DP→HDMI 2.1 active adapters (Club3D, Cable Matters, VMM7100, etc.) or USB‑C docks.
  • Mixed reports: some users achieve 4K120, HDR, and even VRR/Freesync with specific adapters and custom firmware; others say no adapter reliably delivers 4:4:4 + HDR + VRR + 4K120 without glitches.
  • Many point out adapters usually don’t officially support VRR, and firmware quality is hit‑or‑miss.

Legal, DRM, and Standards Politics

  • Heated debate over IP: some see HDMI Forum as a rent‑seeking cartel akin to scientific publishers; others defend “they own the IP, they can charge.”
  • Distinction raised between patents (FRAND pools), branding/certification (use of “HDMI 2.1” name/logo), and trade secrets/NDAs.
  • Clean‑room reverse engineering and anonymous/open‑source implementations are discussed; consensus is they’d be risky for companies but plausible for hobbyists, especially if marketed as “HDMI‑compatible” rather than certified.
  • Several call for laws requiring public, royalty‑free standards for de‑facto infrastructure technologies.

Smart TVs, “Dumb” Displays, and a Possible Steam TV

  • Strong resentment toward smart TV OSes (ads, forced launchers, unremovable apps like Copilot, pop‑ups).
  • Popular coping strategies:
    • Buy a TV, update once, disconnect from internet, use external box (Apple TV, Roku, etc.).
    • Avoid TVs entirely and use large monitors or projectors, though size, cost, and refresh‑rate constraints apply.
  • Many express interest in a “Steam TV” or at least a high‑end, dumb, gamer‑focused display with VRR/HDR and open specs, but some warn that integrated compute ages faster than panels and prefer a separable box + display model.