SUMMARY Enabling HDR for my MSI Optix MAG342CQR using an Intel ARC A770 card results in a corrupted display (see attachments). Note, KWIN_DRM_ALLOW_INTEL_COLORSPACE=1 is in the environment, to make this setting show up at all. Considering that the state of HDR on Intel platforms is experimental this may very well be an i915 bug. But I am reporting it here because it worked mostly okay in kwin 6.0, but is now no longer working at all in 6.1. STEPS TO REPRODUCE 1. add KWIN_DRM_ALLOW_INTEL_COLORSPACE=1 to system wide environment 2. restart 3. enable HDR in display settings OBSERVED RESULT See attachments EXPECTED RESULT No corrupted display SOFTWARE/OS VERSIONS Linux/KDE Plasma: Gentoo Linux KDE Plasma Version: 6.1.0 KDE Frameworks Version: 6.3.0 Qt Version: 6.7.2 ADDITIONAL INFORMATION Please let me know if and how I can provide i915/kwin debug logs that may be helpful.
Photos exceed file size limit, so here's a google drive link instead: https://drive.google.com/file/d/1wSD4oq04pddjrKf3r-Byat96LMuEb8DN/view?usp=sharing
KWin now uses 16 bit floating point dmabufs instead of an opengl texture for compositing, which will be the cause of this issue. RadeonSi doesn't handle them well either (https://gitlab.freedesktop.org/mesa/mesa/-/issues/10875), I assume Intel also just has problems with the used modifier on some hardware (it works fine on all tested Intel integrated GPUs so far). If I provide a patch that prints the used format + modifier, would you apply that and make a bug report for Mesa with that information? I'll expand the workaround we have in place for AMD to Intel, but we really need this fixed in the drivers.
> If I provide a patch that prints the used format + modifier, would you apply that and make a bug report for Mesa with that information? I'll expand the workaround we have in place for AMD to Intel, but we really need this fixed in the drivers. Sure, no problem, happy to help!
Today I gave the new Xe driver a try, and found that with this kernel driver I have the same HDR issue. But I guess that makes sense if the issue is in the mesa driver.
Created attachment 171374 [details] log format and modifier of the shadow buffer Okay, here's the patch to get the format information
Thanks, applied, and reported a new bug for mesa: https://gitlab.freedesktop.org/mesa/mesa/-/issues/11460