SUMMARY KWin used to support an environment variable to overwrite the selection of which drm device to use. This got lost in commit https://invent.kde.org/plasma/kwin/-/commit/b50f7478769c1b50b48d5f0e9201a8e4b7e275ef STEPS TO REPRODUCE 1. Use weird vivante hardware with a card0 and a card1 which doesn't support GL on /dev/dri/card0 2. specify KWIN_DRM_DEVICE to point to /dev/dri/card1 OBSERVED RESULT /dev/dri/card0 is used and KWin doesn't work EXPECTED RESULT /dev/dri/card1 is used and KWin works
Would it be sufficient if we introduce an environment variable with a slightly different name, KWIN_DRM_DEVICES?
(In reply to Vlad Zahorodnii from comment #1) > Would it be sufficient if we introduce an environment variable with a > slightly different name, KWIN_DRM_DEVICES? sure
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/917
Git commit 8d9e47ee227c16e81dd0a6db3f12a94fcd14dc48 by Vlad Zahorodnii. Committed on 01/05/2021 at 12:14. Pushed by vladz into branch 'master'. platforms/drm: Introduce KWIN_DRM_DEVICES This allows to instruct kwin what drm devices must be used explicitly. M +24 -9 src/plugins/platforms/drm/drm_backend.cpp M +1 -1 src/plugins/platforms/drm/drm_backend.h M +1 -1 src/plugins/platforms/drm/drm_gpu.cpp M +3 -3 src/plugins/platforms/drm/drm_gpu.h M +2 -2 src/plugins/platforms/fbdev/fb_backend.cpp M +2 -2 src/udev.cpp M +1 -1 src/udev.h https://invent.kde.org/plasma/kwin/commit/8d9e47ee227c16e81dd0a6db3f12a94fcd14dc48