Created attachment 168042 [details] Monitor input information with both displays set to HDR enabled STEPS TO REPRODUCE 1. Connect two HDR monitors (in my case over two DP1.4a -> HDMI 2.1 Adapters, due to amdgpu limitations) 2. Enable HDR on both OBSERVED RESULT At least one output will have washed out colors, the same way an HDR video looks when you play it on an SDR screen without tone mapping. Sometimes I also got a pure black screen. SOFTWARE/OS VERSIONS Linux/KDE Plasma: EndeavourOS KDE Plasma Version: 6.0.3 In the attached image, VRR only switches to FREESYNC PREMIUM, once it gets an HDR signal. kscreen-doctor -o Output: 1 DP-1 enabled connected priority 1 DisplayPort Modes: 0:3840x2160@60! 1:4096x2160@120 2:4096x2160@120 3:4096x2160@100 4:4096x2160@60 5:4096x2160@60 6:4096x2160@50 7:4096x2160@30 8:4096x2160@30 9:4096x2160@25 10:4096x2160@24 11:4096x2160@24 12:3840x2160@120* 13:3840x2160@120 14:3840x2160@100 15:3840x2160@96 16:3840x2160@72 17:3840x2160@60 18:3840x2160@60 19:3840x2160@60 20:3840x2160@50 21:3840x2160@50 22:3840x2160@48 23:3840x2160@30 24:3840x2160@30 25:3840x2160@25 26:3840x2160@24 27:3840x2160@24 28:2560x1440@120 29:1920x1200@60 30:1920x1080@120 31:1920x1080@120 32:1920x1080@100 33:1920x1080@60 34:1920x1080@60 35:1920x1080@60 36:1920x1080@50 37:1920x1080@30 38:1920x1080@30 39:1920x1080@25 40:1920x1080@24 41:1920x1080@24 42:1600x1200@60 43:1680x1050@60 44:1280x1024@60 45:1440x900@60 46:1280x800@60 47:1152x864@60 48:1280x720@60 49:1280x720@60 50:1280x720@50 51:1024x768@60 52:800x600@60 53:720x576@50 54:720x480@60 55:720x480@60 56:720x480@60 57:720x480@60 58:640x480@60 59:640x480@60 60:720x400@70 61:1600x1200@60 62:1280x1024@60 63:1024x768@60 64:2560x1600@60 65:1920x1200@60 66:1280x800@60 67:3840x2160@60 68:3200x1800@60 69:2880x1620@60 70:2560x1440@60 71:1920x1080@60 72:1600x900@60 73:1368x768@60 74:1280x720@60 Geometry: 2560,0 2560x1440 Scale: 1.5 Rotation: 1 Overscan: 0 Vrr: Automatic RgbRange: unknown HDR: enabled SDR brightness: 160 nits SDR gamut wideness: 0% Peak brightness: 800 nits, overridden with: 800 nits Max average brightness: 0 nits Min brightness: 0 nits Wide Color Gamut: enabled ICC profile: none Output: 2 DP-2 enabled connected priority 2 DisplayPort Modes: 0:3840x2160@60! 1:4096x2160@120 2:4096x2160@120 3:4096x2160@100 4:4096x2160@60 5:4096x2160@60 6:4096x2160@50 7:4096x2160@30 8:4096x2160@30 9:4096x2160@25 10:4096x2160@24 11:4096x2160@24 12:3840x2160@120* 13:3840x2160@120 14:3840x2160@100 15:3840x2160@96 16:3840x2160@72 17:3840x2160@60 18:3840x2160@60 19:3840x2160@60 20:3840x2160@50 21:3840x2160@50 22:3840x2160@48 23:3840x2160@30 24:3840x2160@30 25:3840x2160@25 26:3840x2160@24 27:3840x2160@24 28:2560x1440@120 29:1920x1200@60 30:1920x1080@120 31:1920x1080@120 32:1920x1080@100 33:1920x1080@60 34:1920x1080@60 35:1920x1080@60 36:1920x1080@50 37:1920x1080@30 38:1920x1080@30 39:1920x1080@25 40:1920x1080@24 41:1920x1080@24 42:1600x1200@60 43:1680x1050@60 44:1280x1024@60 45:1440x900@60 46:1280x800@60 47:1152x864@60 48:1280x720@60 49:1280x720@60 50:1280x720@50 51:1024x768@60 52:800x600@60 53:720x576@50 54:720x480@60 55:720x480@60 56:720x480@60 57:720x480@60 58:640x480@60 59:640x480@60 60:720x400@70 61:1600x1200@60 62:1280x1024@60 63:1024x768@60 64:2560x1600@60 65:1920x1200@60 66:1280x800@60 67:3840x2160@60 68:3200x1800@60 69:2880x1620@60 70:2560x1440@60 71:1920x1080@60 72:1600x900@60 73:1368x768@60 74:1280x720@60 Geometry: 0,0 2560x1440 Scale: 1.5 Rotation: 1 Overscan: 0 Vrr: Automatic RgbRange: unknown HDR: enabled SDR brightness: 160 nits SDR gamut wideness: 0% Peak brightness: 800 nits, overridden with: 800 nits Max average brightness: 0 nits Min brightness: 0 nits Wide Color Gamut: enabled ICC profile: none
HDR with DisplayPort is unfortunately still / again kind of a work in progress upstream: https://gitlab.freedesktop.org/drm/amd/-/issues/3079 Until that's resolved, washed out colors are pretty much expected
Does that not imply that it should not work at all?
Upon switching from my Plasma desktop environment to tty3 and then returning, the HDR on my monitors will be activated at random. Either the left monitor, the right monitor, or both simultaneously. Consequently, it is confirmed that both monitors are capable of receiving an HDR signal at the same time, and I will update the title to reflect this finding. Could anyone advise on the steps I should follow to diagnose this problem further?
> Does that not imply that it should not work at all? That issue is consistent with DisplayPort, not flaky like yours. If switching from and to ttys change things, then that means you're seeing a different driver bug. Please report it at https://gitlab.freedesktop.org/drm/amd/-/issues