511101 2025-10-25 15:58:30 +0000 kwin 6.5.0 seems to break gamescope HDR support 2025-10-26 13:49:27 +0000 1 1 4 Plasma kwin colour-management 6.5.0 Other Linux RESOLVED UPSTREAM NOR normal --- 0 fk-kde-bugs kwin-bugs-null xaver.hugl 0 oldest_to_newest 2465022 0 fk-kde-bugs 2025-10-25 15:58:30 +0000 SUMMARY After the update to 6.5.0 I'm not able to use HDR within gamescope anymore. HDR through mpv / proton-ge (wayland) works as expected. STEPS TO REPRODUCE 1. Enable HDR 2. start a fullscreen game in gamescope using --hdr-enabled (i.e., gamescope -f -W 1920 -H 1080 --hdr-enabled --hdr-debug-force-output --backend wayland --force-grab-cursor --adaptive-sync --hdr-itm-target-nits 825 --rt -- %command%) OBSERVED RESULT No HDR visible. In-game option for HDR disabled. Using WAYLAND_DEBUG and grepping for "wp_image_description_creator_params_v1" stays empty I can see: [gamescope] [Info] xdg_backend: uMaxContentLightLevel: 80 [gamescope] [Info] xdg_backend: HDR INFO [gamescope] [Info] xdg_backend: cv_hdr_enabled: true [gamescope] [Info] xdg_backend: uTF: GAMMA22 [gamescope] [Info] xdg_backend: bExposeHDRSupport: false [gamescope] [Info] xdg_backend: uMaxContentLightLevel: 840 (<--- switching HDR on/off) [gamescope] [Info] xdg_backend: HDR INFO [gamescope] [Info] xdg_backend: cv_hdr_enabled: true [gamescope] [Info] xdg_backend: uTF: GAMMA22 [gamescope] [Info] xdg_backend: bExposeHDRSupport: false With gamescope option "--hdr-debug-force-output" I get the following output: pEngineName: (null) engineVersion: 0 apiVersion: 4198400 [gamescope] [Warn] xwm: got the same buffer committed twice, ignoring. [Gamescope WSI] Creating Gamescope surface: xid: 0x200009b [Gamescope WSI] Atom of T was wrong type. Expected XCB_ATOM_CARDINAL. [Gamescope WSI] Made gamescope surface for xid: 0x200009b [Gamescope WSI] Surface state: steam app id: 548430 window xid: 0x200009b wayland surface res id: 5 layer client flags: 0x4 server hdr output enabled: true hdr formats exposed to client: true [Gamescope WSI] Creating swapchain for xid: 0x200009b - oldSwapchain: (nil) - provided minImageCount: 3 - minImageCount: 3 - format: VK_FORMAT_A2B10G10R10_UNORM_PACK32 - colorspace: VK_COLOR_SPACE_SRGB_NONLINEAR_KHR - flip: true [Gamescope WSI] Created swapchain for xid: 0x200009b swapchain: 0x7f47d0110180 - imageCount: 3 but still no HDR option in the game. EXPECTED RESULT HDR should work SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.5.0 KDE Frameworks Version: 6.19.0 Qt Version: 6.10.0 Kernel Version: 6.17.4-arch2-1 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 PRO 4750U with Radeon Graphics Memory: 48 GiB of RAM (46.3 GiB usable) Graphics Processor: AMD Radeon Graphics Gamescope version: 3.16.17 and git ADDITIONAL INFORMATION 2465118 1 xaver.hugl 2025-10-25 21:28:57 +0000 This needs fixing in gamescope, see https://github.com/ValveSoftware/gamescope/pull/1999 2465219 2 fk-kde-bugs 2025-10-26 10:07:34 +0000 (In reply to Zamundaaa from comment #1) > This needs fixing in gamescope, see > https://github.com/ValveSoftware/gamescope/pull/1999 Thanks, this fixes my issue. Wonder whether a detection of "HDR is enabled" is actually useful there, or should only depend on --hdr-enabled and further whatever the user configures in the app. Then kwin should just take care of HDR to SDR transformation if the setting is off. 2465251 3 xaver.hugl 2025-10-26 13:49:27 +0000 Yeah, mirroring whether the compositor supports HDR might be better