I’ve been having some issues with HDR support on my Arch install (currently kwin 6.5.2-1.1). it lets me switch to HDR mode, the monitor confirms it’s in HDR mode, and the calibration works correctly, showing that 1000 nits is my max brightness, and the SDR brightness setting works as expected. however, actual HDR content (movies played with mpv and games played with proton-ge and PROTON_ENABLE_WAYLAND=1 PROTON_ENABLE_HDR=1) never seem to actually display any brightness higher than the max brightness for hdr content.
for comparison, both gnome and hyprland correctly detect the max HDR brightness of my display and things look correct. I think the last time I opened KDE was a few months ago, and it was working then, so I’m not really sure what’s broken in the mean time, but it ain’t workin’ now on my box.
I’ve tried every color accuracy setting (prefer efficiency with detected 10 bits/channel, prefer accuracy with every setting from 10 to 16 bits/channel). kscreen-doctor -o also shows that kwin is seeing my settings correctly, and thinks it’s doing the right thing. but it really isn’t. so I’m pretty baffled.
anyone have suggestions on how to diagnose this further, and fix it? lots of folks are using current kde and having no problems with hdr, so I suspect something is messed up on my system in particular, but I can’t find it.
ahhh damn, I really hoped that’d do it, but no such luck. did the full KDE upgrade today, problem persists. did some playing around in-game in Elden Ring with its HDR calibration, it setting the max brightness does nothing (when it should have a super obvious impact on displayed brightness), and turning HDR off results in a much higher contrast picture than with HDR on. both of those are signs that it’s just doing SDR tone mapping to the game rather than actually displaying the content as native HDR.
Output: 1 DP-2 8adb3b5c-d6bc-4eba-b47d-9bcbe3f026c3
enabled
connected
priority 1
DisplayPort
replication source:0
Modes: 1:3840x2160@60.00! 2:3840x2160@239.99* 3:3840x2160@120.00 4:3840x2160@119.88 5:3840x2160@60.00 6:3840x2160@59.94 7:3840x2160@50.00 8:3840x2160@30.00 9:3840x2160@29.97 10:3840x2160@25.00 11:3840x2160@24.00 12:3840x2160@23.98 13:2560x1440@239.97 14:2560x1440@120.00 15:2560x1440@59.95 16:1920x1200@60.00 17:1920x1080@240.00 18:1920x1080@120.00 19:1920x1080@119.88 20:1920x1080@60.00 21:1920x1080@60.00 22:1920x1080@59.94 23:1920x1080@50.00 24:1920x1080@30.00 25:1920x1080@29.97 26:1920x1080@25.00 27:1920x1080@24.00 28:1920x1080@23.98 29:1600x1200@60.00 30:1680x1050@60.00 31:1600x900@60.00 32:1280x1024@75.03 33:1280x1024@60.02 34:1440x900@60.00 35:1280x800@60.00 36:1152x864@75.00 37:1280x720@60.00 38:1280x720@59.94 39:1280x720@50.00 40:1024x768@75.03 41:1024x768@60.00 42:800x600@75.00 43:800x600@60.32 44:720x576@50.00 45:720x480@60.00 46:720x480@60.00 47:720x480@59.94 48:720x480@59.94 49:640x480@75.00 50:640x480@60.00 51:640x480@59.94 52:640x480@59.94 53:720x400@70.08 54:1600x1200@239.94 55:1280x1024@239.78 56:1024x768@239.74 57:2560x1600@59.99 58:2560x1600@239.94 59:1920x1200@239.94 60:1280x800@239.70 61:3200x1800@59.96 62:3200x1800@239.87 63:2880x1620@59.96 64:2880x1620@239.94 65:1600x900@239.83 66:1368x768@59.88 67:1368x768@239.74 68:1280x720@239.96
Geometry: 0,0 2954x1662
Scale: 1.3
Rotation: 1
Overscan: 0
Vrr: Never
RgbRange: unknown
HDR: enabled
SDR brightness: 220 nits
SDR gamut wideness: 0%
Peak brightness: 1000 nits, overridden with: 1000 nits
Max average brightness: 277 nits
Min brightness: 0.0006 nits
Wide Color Gamut: enabled
ICC profile: none
Color profile source: sRGB
Color power preference: prefer efficiency and performance
Brightness control: supported, set to 100% and dimming to 100%
DDC/CI: disallowed
Color resolution: automatic (10), range: [8; 16] bits per color
Allow EDR: unsupported
Sharpness control: unsupported
Output: 2 HDMI-A-1 1232e034-3fa9-4629-9f91-0191d88cc8b2
enabled
connected
priority 2
HDMI
replication source:1
Modes: 69:1920x1080@60.00*! 70:1920x1080@59.94 71:1920x1080@50.00 72:1920x1080@24.00 73:1920x1080@23.98 74:2880x576@50.00 75:2880x576@50.00 76:2880x480@60.00 77:2880x480@60.00 78:2880x480@59.94 79:2880x480@59.94 80:1280x720@60.00 81:1280x720@60.00 82:1280x720@59.94 83:1280x720@50.00 84:1280x720@50.00 85:1440x576@50.00 86:1440x576@50.00 87:1440x480@60.00 88:1440x480@60.00 89:1440x480@59.94 90:1440x480@59.94 91:720x576@50.00 92:720x576@50.00 93:720x480@60.00 94:720x480@60.00 95:720x480@59.94 96:720x480@59.94 97:720x480@59.94 98:640x480@60.00 99:640x480@59.94 100:640x480@59.94 101:1280x1024@59.90 102:1024x768@59.92 103:1280x800@59.81 104:1600x900@59.95 105:1368x768@59.88
Geometry: 0,0 2954x1662
Scale: 0.65
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: none
Color profile source: sRGB
Color power preference: prefer efficiency and performance
Brightness control: supported, set to 100% and dimming to 100%
Color resolution: automatic (10), range: [8; 16] bits per color
Allow EDR: unsupported
Sharpness control: unsupported
so I didn’t get the 6.5.3 release even if I did a big KDE update. I’ll try updating again, making sure I’ve got the latest release code for sure, then see how it looks.
unfortunately, even after making sure I’m actually on the latest release, still isn’t working properly, so hopefully some of this output will be helpful.
