RTX 5070 (Blackwell) 610.43.02: HDR/BT2020 impossible on DP - atomic test EINVAL on Colorspace, EGLImage FBO attach fails (KDE Plasma 6.6.5 Wayland)

Graphics / Linux Linux
1

System

  • GPU: NVIDIA GeForce RTX 5070 (GB205), nvidia-open 610.43.02
  • Kernel: 7.0.11-arch1-1 (Arch Linux)
  • Desktop: KDE Plasma 6.6.5 Wayland, kwin 6.6.5-4 - includes the backported fix for KDE bug 520842 (commit cac455ad, “don’t attempt to bypass non-bypassable colorops”), so this is not the known KWin colorops issue
  • Monitor: LG UltraGear 27" 2560x1440@165 on DP (HDR10 per EDID, HDR Static Metadata + Colorimetry blocks present; full EDID attached)
  • Two other SDR monitors on the same card (DP + HDMI)

Problem
Enabling HDR (or Wide Color Gamut alone) in KDE Display Settings always fails: the driver rejects the atomic commit with EINVAL, and KWin’s GL renderer floods GL_INVALID_OPERATION (<image> and <target> are incompatible) + GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT while testing HDR buffer configurations (tens of thousands of occurrences; on kwin builds without the 520842 fix this blacked out all outputs until the HDR monitor was power-cycled).

Ruled out by testing (details in attached kwin-journal-excerpts.txt):

  • Refresh rate / link bandwidth: fails identically at 165, 144, 120 and 60 Hz
  • Multi-monitor interaction: fails with the HDR monitor as the only enabled output
  • HDR metadata: enabling WCG alone (Colorspace=BT2020_RGB only, no HDR_OUTPUT_METADATA) is rejected the same way - so the Colorspace property itself appears to be the trigger
  • DRM color pipeline: identical failure with nvidia_drm.color_pipeline=1 (default) and =0 (initramfs rebuilt and verified via /sys each time)
  • Compositor bug: kwin carries the cac455ad colorops fix; behavior unchanged

Other observations

  • The rejection is completely silent on the kernel side - no nvidia/nvidia-modeset/drm messages in dmesg at any log level during the failed commits
  • The DP connector exposes Colorspace (Default/BT2020_RGB/BT2020_YCC) and HDR_OUTPUT_METADATA, but no max bpc property (drm-props-DP-3.txt attached)
  • HDR on this monitor works on the same hardware under Windows

Reproduction

  1. Plasma 6.6.5 Wayland session, driver 610.43.02, HDR-capable DP monitor

  2. System Settings → Display & Monitor → enable HDR (or just WCG), or kscreen-doctor output.DP-3.hdr.enable

  3. Result: “applying config failed! The driver rejected the output configuration”; journal shows Atomic modeset test failed! Invalid argument plus the GL framebuffer error flood

  4. drm-props-DP-3.txt (3.0 KB)

    kscreen-outputs.txt (2.8 KB)

    kwin-journal-excerpts.txt (1.6 KB)

    nvidia-bug-report.log.gz (553.3 KB)