Created attachment 179947 [details] edid-decode output SUMMARY Missing high-bit (HDR/WCG) support in Wayland on Dell UP3216Q, although monitor supports 30-bit colors, it is also seen via edid. STEPS TO REPRODUCE - OBSERVED RESULT 1. "Display & Monitor" -> "Display Configuration" -> No HDR/WCG 2. kscreen-doctor -o -> HDR / Wide Color Gamut: incapable EXPECTED RESULT HDR and/or WCG functions. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 24.10 KDE Plasma Version: 6.1.5 KDE Frameworks Version: 6.6.0 Qt Version: 6.6.2. ADDITIONAL INFORMATION * Tested on KDE 6.3.3. (via Kubuntu 25.04 daily) with the same outcome. * Dell UP3216Q is technically more of a "WCG monitor" with 10 bpc, although back in 2015 I think they just called it HDR (?) as terminology was more flaky. Under Windows it did run in HDR mode, when I tested some 4 years ago, not in 2015/2016 for sure. * I will give KWIN_FORCE_ASSUME_HDR_SUPPORT a shot once on Kubuntu 25.04 as the patch went to 6.3. production and comes with 6.3.4.
Created attachment 179948 [details] stdout from kscreen-doctor -o
Also, just a thought, I see that KWIN_FORCE_ASSUME_HDR_SUPPORT will effectively force m_hdrMetadata->supportsPQ = *s_forceHdrSupport; m_hdrMetadata->supportsBT2020 = *s_forceHdrSupport; I am sure that in my case "supportsBT2020" should do well (drm_info reports: ABGR2101010). Whereas "supportsPQ" has more to do with "HDR" per se, i.e., brightness, although, arguably the 10-bit range is for sure a higher dynamic range than the 8-bit range :)
Bit depth and HDR are not the same thing. KWin always uses 10 bits per color (or up to 16 if you set the output to "prefer color accuracy") it's not something you have to enable. Your display doesn't support either BT2020 or PQ, so it's correct that you can't enable them.