Thanks! I have set up a dev machine for this but am having trouble runing kwin_wayland directly there. Logging in with sddm takes ages the first time (~a few minutes and I’d thought it had hung) but does start kwin_wayland eventually. The next login was quite quick.
pstree:
│ ├─kwin_wayland_wr─┬─kwin_wayland─┬─Xwayland
│ │ │ ├─maliit-keyboard───11*[{maliit-keyboard}]
│ │ │ └─9*[{kwin_wayland}]
│ │ └─{kwin_wayland_wr}
launched with:
/usr/bin/kwin_wayland --wayland-fd 7 --socket wayland-0 --xwayland-fd 8 --xwayland-fd 9 --xwayland-display :0 --xwayland-xauthority /run/user/1000/xauth_CZpTmd --xwayland
If instead I boot into runlevel 3 and try running kwin_wayland myself I get the following:
$ sudo modprobe nvidia_drm modeset=1
$ ./build/bin/kwin_wayland --drm dolphin
kwin_core: Failed to activate /org/freedesktop/login1/session/_33 session. Maybe another compositor is running?
Accepting client connections on sockets: QList("wayland-0")
kwin_wayland_drm: failed to open drm device at "/dev/dri/card0"
kwin_wayland_drm: No suitable DRM devices have been found
Same when running kwin_wayland from kwin-wayland-6.0.3.1-2.fc40.x86_64. My user is in the video group but same when running as root with sudo env XDG_RUNTIME_DIR=/tmp ./build/bin/kwin_wayland dolphin. I noticed testDrm and that seems to run and pass:
./build/bin/testDrm
********* Start testing of DrmTest *********
Config: Using QtTest library 6.7.2, Qt 6.7.2 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 14.2.1 20240801 (Red Hat 14.2.1-1)), fedora 40
PASS : DrmTest::initTestCase()
QWARN : DrmTest::testAmsDetection() kwin_wayland_drm: Failed to create any plane. Falling back to legacy mode on GPU "/dev/dri/card0"
...
QWARN : DrmTest::testVrrChange() kwin_wayland_drm: Driver doesn't advertise any formats for this plane. Falling back to XRGB8888 without explicit modifiers
PASS : DrmTest::testVrrChange()
PASS : DrmTest::cleanupTestCase()
Totals: 13 passed, 0 failed, 1 skipped, 0 blacklisted, 44ms
********* Finished testing of DrmTest *********
This time using akmod-nvidia.x86_64 3:560.35.03-1.fc40 from @rpmfusion-nonfree-updates rather than the .run file from nvidia dot com. When loading nvidia_drm modeset=1 I’m not seeing any errors from dmesg:
[ 2683.438370] nvidia-nvlink: Nvlink Core is being initialized, major device number 236
[ 2683.440242] nvidia 0000:01:00.0: vgaarb: VGA decodes changed: olddecodes=none,decodes=none:owns=io+mem
[ 2683.640659] NVRM: loading NVIDIA UNIX x86_64 Kernel Module 560.35.03 Fri Aug 16 21:39:15 UTC 2024
[ 2683.742151] nvidia_uvm: module uses symbols nvUvmInterfaceDisableAccessCntr from proprietary module nvidia, inheriting taint.
[ 2683.893789] nvidia-uvm: Loaded the UVM driver, major device number 234.
[ 2683.960984] nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver for UNIX platforms 560.35.03 Fri Aug 16 21:21:48 UTC 2024
[ 2683.968186] [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
[ 2685.673623] [drm] Initialized nvidia-drm 0.0.0 20160202 for 0000:01:00.0 on minor 0
[ 2685.673632] nvidia 0000:01:00.0: vgaarb: deactivate vga console
[ 2685.757645] fbcon: nvidia-drmdrmfb (fb0) is primary device
[ 2685.802303] Console: switching to colour frame buffer device 240x67
[ 2685.819856] nvidia 0000:01:00.0: [drm] fb0: nvidia-drmdrmfb frame buffer device
I found some logs from journalctl -b | grep -i 'wayland.*]: '. I think these are just from sddm runs, not my own:
Sep 22 21:27:08 waydev sddm-helper-start-wayland[18097]: "No backend specified, automatically choosing drm\n"
Sep 22 21:27:08 waydev sddm-helper-start-wayland[18097]: "Accepting client connections on sockets: QList(\"wayland-0\")\n"
Sep 22 21:27:09 waydev sddm-helper-start-wayland[18097]: "QSoundEffect(pulseaudio): Error decoding source file:///usr/share/maliit/keyboard2/sounds/key_tick2_quiet.wav\n"
Sep 22 21:27:11 waydev sddm-helper-start-wayland[18097]: "QSGContext::initialize: depth buffer support missing, expect rendering errors\nQSGContext::initialize: stencil buffer support missing, expect rendering errors\n"
Sep 22 21:27:19 waydev sddm-helper-start-wayland[18097]: "kwin_wayland_drm: Presentation failed! Permission denied\n"
Sep 22 21:27:19 waydev sddm-helper-start-wayland[18097]: Stopping... "kwin_wayland"
Sep 22 21:27:20 waydev kwin_wayland[18448]: No backend specified, automatically choosing drm
Sep 22 21:27:21 waydev kwin_wayland_wrapper[18528]: The XKEYBOARD keymap compiler (xkbcomp) reports:
Sep 22 21:27:21 waydev kwin_wayland_wrapper[18528]: > Warning: Unsupported maximum keycode 708, clipping.
Sep 22 21:27:21 waydev kwin_wayland_wrapper[18528]: > X11 cannot support keycodes above 255.
Sep 22 21:27:21 waydev kwin_wayland_wrapper[18528]: Errors from xkbcomp are not fatal to the X server
Sep 22 21:27:29 waydev kwin_wayland[18448]: kwin_wayland_drm: Pageflip timed out! This is a kernel bug
Sep 22 21:27:34 waydev kwin_wayland[18448]: kwin_wayland_drm: Pageflip timed out! This is a kernel bug
...
Sep 22 21:33:08 waydev kwin_wayland[19857]: kf.windowsystem: static bool KX11Extras::mapViewport() may only be used on X11
Sep 22 21:39:29 waydev kwin_wayland[19857]: qt.dbus.integration: QDBusConnection: couldn't handle call to Teardown, no slot matched
Sep 22 21:39:29 waydev kwin_wayland[19857]: qt.dbus.integration: QDBusConnection: couldn't handle call to Teardown, no slot matched
Sep 22 21:39:29 waydev kwin_wayland[19857]: qt.dbus.integration: Could not find slot Krunner1Adaptor::Teardown
Is it possible kwin_wayland falls back to something else when run from sddm? Is there any extra config needed to run it manually?