Bug 456569 - External monitor goes black when video player is fullscreen
Summary: External monitor goes black when video player is fullscreen
Status: RESOLVED WORKSFORME
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (other bugs)
Version First Reported In: 5.25.2
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: multiscreen, wayland-only
: 456997 (view as bug list)
Depends on:
Blocks:
 
Reported: 2022-07-10 23:56 UTC by Danilo
Modified: 2024-06-22 03:47 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Output of journalctl --boot 0 | grep kwin_wayland (16.00 KB, text/x-log)
2022-07-10 23:56 UTC, Danilo
Details
kwin logs and drm logs (1.49 MB, application/x-7z-compressed)
2022-07-11 01:30 UTC, Danilo
Details
`journalctl --boot 0 | grep kwin_wayland` with `QT_LOGGING_RULES="kwin_*.debug=true"` (5.64 KB, application/x-7z-compressed)
2022-07-11 21:59 UTC, Danilo
Details

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Description Danilo 2022-07-10 23:56:23 UTC
Created attachment 150526 [details]
Output of journalctl --boot 0 | grep kwin_wayland

STEPS TO REPRODUCE
1. Open VLC in external monitor (also happens with Celluloid, Haruna, Kodi...) 
2. Open a video file
3. Make it fullscreen

OBSERVED RESULT
When the menu with the progress bar disappears, the external monitor's screen goes black for a couple of seconds. Move the mouse, the progress bar comes back normally. The screen will continue to go black every time the menu with the progress bar disappears.

EXPECTED RESULT
Monitor screen keeps on, displaying the video.

SOFTWARE/OS VERSIONS
Linux: 5.15.53-2-lts
(available in About System)
KDE Plasma Version: 5.25.2
KDE Frameworks Version: 5.96.0
Qt Version: 5.15.5

ADDITIONAL INFORMATION
Here's a reddit post where I've attached a video showing the bug: https://www.reddit.com/r/kde/comments/vunmtk/external_monitor_goes_black_when_video_player_is/
Comment 1 Danilo 2022-07-11 00:00:38 UTC
Comment on attachment 150526 [details]
Output of journalctl --boot 0 | grep kwin_wayland

>Jul 10 16:36:36 artemis kwin_wayland_wrapper[877]: No backend specified through command line argument, trying auto resolution
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: OpenGL vendor string:                   AMD
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: OpenGL renderer string:                 AMD RENOIR (LLVM 14.0.6, DRM 3.42, 5.15.53-2-lts)
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: OpenGL version string:                  4.6 (Core Profile) Mesa 22.1.3
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: OpenGL shading language version string: 4.60
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: Driver:                                 RadeonSI
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: GPU class:                              Vega
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: OpenGL version:                         4.6
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: GLSL version:                           4.60
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: Mesa version:                           22.1.3
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: Linux kernel version:                   5.15.53
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: Requires strict binding:                no
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: GLSL shaders:                           yes
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: Texture NPOT support:                   yes
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[877]: Virtual Machine:                        no
>Jul 10 16:36:37 artemis kwin_wayland[877]: kwin_xkbcommon: XKB: inet:323:58: unrecognized keysym "XF86EmojiPicker"
>Jul 10 16:36:37 artemis kwin_wayland[877]: kwin_xkbcommon: XKB: inet:324:58: unrecognized keysym "XF86Dictate"
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[909]: (WW) Option "-listen" for file descriptors is deprecated
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[909]: Please use "-listenfd" instead.
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[909]: (WW) Option "-listen" for file descriptors is deprecated
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[909]: Please use "-listenfd" instead.
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[962]: The XKEYBOARD keymap compiler (xkbcomp) reports:
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[962]: > Warning:          Unsupported maximum keycode 708, clipping.
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[962]: >                   X11 cannot support keycodes above 255.
>Jul 10 16:36:37 artemis kwin_wayland_wrapper[962]: Errors from xkbcomp are not fatal to the X server
>Jul 10 16:38:38 artemis kwin_wayland[877]: This plugin does not support raise()
>Jul 10 16:38:51 artemis kwin_wayland[877]: This plugin does not support raise()
>Jul 10 17:12:20 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{05873055-23ba-43b5-9c5c-48c6b580b630}"
>Jul 10 17:12:20 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{05873055-23ba-43b5-9c5c-48c6b580b630}"
>Jul 10 17:12:20 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{05873055-23ba-43b5-9c5c-48c6b580b630}"
>Jul 10 17:12:40 artemis kwin_wayland[877]: kwin_libinput: Libinput: event8  - BY Tech Gaming Keyboard: client bug: event processing lagging behind by 37ms, your system is too slow
>Jul 10 17:13:08 artemis kwin_wayland[877]: QMetaProperty::read: Unable to handle unregistered datatype 'KWin::SessionState' for property 'KWin::EffectsHandlerImpl::sessionState'
>Jul 10 17:13:26 artemis kwin_wayland[877]: This plugin does not support raise()
>Jul 10 17:13:26 artemis kwin_wayland[877]: This plugin does not support raise()
>Jul 10 17:15:40 artemis kwin_wayland[877]: kwin_libinput: Libinput: event8  - BY Tech Gaming Keyboard: client bug: event processing lagging behind by 42ms, your system is too slow
>Jul 10 17:16:45 artemis kwin_wayland[877]: kwin_libinput: Libinput: event8  - BY Tech Gaming Keyboard: client bug: event processing lagging behind by 42ms, your system is too slow
>Jul 10 17:28:00 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{21eacee4-db47-448e-8af9-5d4709805fcb}"
>Jul 10 17:28:00 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{21eacee4-db47-448e-8af9-5d4709805fcb}"
>Jul 10 17:28:00 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{21eacee4-db47-448e-8af9-5d4709805fcb}"
>Jul 10 17:49:56 artemis kwin_wayland[877]: QMetaProperty::read: Unable to handle unregistered datatype 'KWin::SessionState' for property 'KWin::EffectsHandlerImpl::sessionState'
>Jul 10 17:49:56 artemis kwin_wayland[877]: QMetaProperty::read: Unable to handle unregistered datatype 'KWin::SessionState' for property 'KWin::EffectsHandlerImpl::sessionState'
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: OpenGL vendor string:                   AMD
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: OpenGL renderer string:                 AMD RENOIR (LLVM 14.0.6, DRM 3.42, 5.15.53-2-lts)
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: OpenGL version string:                  4.6 (Core Profile) Mesa 22.1.3
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: OpenGL shading language version string: 4.60
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: Driver:                                 RadeonSI
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: GPU class:                              Vega
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: OpenGL version:                         4.6
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: GLSL version:                           4.60
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: Mesa version:                           22.1.3
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: X server version:                       1.22.1
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: Linux kernel version:                   5.15.53
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: Requires strict binding:                no
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: GLSL shaders:                           yes
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: Texture NPOT support:                   yes
>Jul 10 17:52:02 artemis kwin_wayland_wrapper[877]: Virtual Machine:                        no
>Jul 10 17:52:02 artemis kwin_wayland[877]: WobblyWindowsConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: BlurConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: ZoomConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: WindowViewConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: SlidingPopupsConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: SlideConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: OverviewConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: KscreenConfig::instance called after the first use - ignoring
>Jul 10 17:52:02 artemis kwin_wayland[877]: DesktopGridConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: OpenGL vendor string:                   AMD
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: OpenGL renderer string:                 AMD RENOIR (LLVM 14.0.6, DRM 3.42, 5.15.53-2-lts)
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: OpenGL version string:                  4.6 (Core Profile) Mesa 22.1.3
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: OpenGL shading language version string: 4.60
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: Driver:                                 RadeonSI
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: GPU class:                              Vega
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: OpenGL version:                         4.6
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: GLSL version:                           4.60
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: Mesa version:                           22.1.3
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: X server version:                       1.22.1
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: Linux kernel version:                   5.15.53
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: Requires strict binding:                no
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: GLSL shaders:                           yes
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: Texture NPOT support:                   yes
>Jul 10 17:52:05 artemis kwin_wayland_wrapper[877]: Virtual Machine:                        no
>Jul 10 17:52:05 artemis kwin_wayland[877]: WobblyWindowsConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: BlurConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: ZoomConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: WindowViewConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: SlidingPopupsConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: SlideConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: OverviewConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: KscreenConfig::instance called after the first use - ignoring
>Jul 10 17:52:05 artemis kwin_wayland[877]: DesktopGridConfig::instance called after the first use - ignoring
>Jul 10 17:52:40 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{ce4ad74b-8eca-4073-85ce-8fc64ee492d7}"
>Jul 10 17:52:40 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{ce4ad74b-8eca-4073-85ce-8fc64ee492d7}"
>Jul 10 17:52:40 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{ce4ad74b-8eca-4073-85ce-8fc64ee492d7}"
>Jul 10 17:52:41 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{ac826f5c-4592-4382-9432-753d02f6b5df}"
>Jul 10 17:52:41 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{ac826f5c-4592-4382-9432-753d02f6b5df}"
>Jul 10 17:52:41 artemis kwin_wayland[877]: kwin_core: Could not find window with uuid "{ac826f5c-4592-4382-9432-753d02f6b5df}"
>Jul 10 17:58:45 artemis kwin_wayland[877]: This plugin does not support raise()
>Jul 10 17:58:45 artemis kwin_wayland[877]: This plugin does not support raise()
>Jul 10 18:06:01 artemis kwin_wayland[877]: kwin_xkbcommon: XKB: inet:323:58: unrecognized keysym "XF86EmojiPicker"
>Jul 10 18:06:01 artemis kwin_wayland[877]: kwin_xkbcommon: XKB: inet:324:58: unrecognized keysym "XF86Dictate"
>Jul 10 18:06:01 artemis kwin_wayland_wrapper[10473]: The XKEYBOARD keymap compiler (xkbcomp) reports:
>Jul 10 18:06:01 artemis kwin_wayland_wrapper[10473]: > Warning:          Unsupported maximum keycode 708, clipping.
>Jul 10 18:06:01 artemis kwin_wayland_wrapper[10473]: >                   X11 cannot support keycodes above 255.
>Jul 10 18:06:01 artemis kwin_wayland_wrapper[10473]: Errors from xkbcomp are not fatal to the X server
>Jul 10 18:06:28 artemis kwin_wayland[877]: kwin_xkbcommon: XKB: inet:323:58: unrecognized keysym "XF86EmojiPicker"
>Jul 10 18:06:28 artemis kwin_wayland[877]: kwin_xkbcommon: XKB: inet:324:58: unrecognized keysym "XF86Dictate"
>Jul 10 18:06:28 artemis kwin_wayland_wrapper[10474]: The XKEYBOARD keymap compiler (xkbcomp) reports:
>Jul 10 18:06:28 artemis kwin_wayland_wrapper[10474]: > Warning:          Unsupported maximum keycode 708, clipping.
>Jul 10 18:06:28 artemis kwin_wayland_wrapper[10474]: >                   X11 cannot support keycodes above 255.
>Jul 10 18:06:28 artemis kwin_wayland_wrapper[10474]: Errors from xkbcomp are not fatal to the X server
>Jul 10 18:08:13 artemis systemd[849]: plasma-kwin_wayland.service: Consumed 6min 49.407s CPU time.
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: No backend specified through command line argument, trying auto resolution
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: OpenGL vendor string:                   AMD
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: OpenGL renderer string:                 AMD RENOIR (LLVM 14.0.6, DRM 3.42, 5.15.53-2-lts)
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: OpenGL version string:                  4.6 (Core Profile) Mesa 22.1.3
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: OpenGL shading language version string: 4.60
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: Driver:                                 RadeonSI
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: GPU class:                              Vega
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: OpenGL version:                         4.6
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: GLSL version:                           4.60
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: Mesa version:                           22.1.3
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: Linux kernel version:                   5.15.53
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: Requires strict binding:                no
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: GLSL shaders:                           yes
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: Texture NPOT support:                   yes
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10683]: Virtual Machine:                        no
>Jul 10 18:08:21 artemis kwin_wayland[10683]: kwin_xkbcommon: XKB: inet:323:58: unrecognized keysym "XF86EmojiPicker"
>Jul 10 18:08:21 artemis kwin_wayland[10683]: kwin_xkbcommon: XKB: inet:324:58: unrecognized keysym "XF86Dictate"
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10713]: (WW) Option "-listen" for file descriptors is deprecated
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10713]: Please use "-listenfd" instead.
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10713]: (WW) Option "-listen" for file descriptors is deprecated
>Jul 10 18:08:21 artemis kwin_wayland_wrapper[10713]: Please use "-listenfd" instead.
>Jul 10 18:08:22 artemis kwin_wayland_wrapper[10765]: The XKEYBOARD keymap compiler (xkbcomp) reports:
>Jul 10 18:08:22 artemis kwin_wayland_wrapper[10765]: > Warning:          Unsupported maximum keycode 708, clipping.
>Jul 10 18:08:22 artemis kwin_wayland_wrapper[10765]: >                   X11 cannot support keycodes above 255.
>Jul 10 18:08:22 artemis kwin_wayland_wrapper[10765]: Errors from xkbcomp are not fatal to the X server
>Jul 10 18:09:44 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{add478a1-8f51-4c19-96e7-a83e15869da9}"
>Jul 10 18:09:44 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{add478a1-8f51-4c19-96e7-a83e15869da9}"
>Jul 10 18:09:44 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{add478a1-8f51-4c19-96e7-a83e15869da9}"
>Jul 10 18:13:40 artemis kwin_wayland[10683]: kf.service.services: The desktop entry file "/usr/share/applications/kcm_krunnersettings.desktop" has Type= "Application" but no Exec line
>Jul 10 18:13:40 artemis kwin_wayland[10683]: kf.service.sycoca: Invalid Service :  "/usr/share/applications/kcm_krunnersettings.desktop"
>Jul 10 18:18:36 artemis kwin_wayland[10683]: This plugin does not support raise()
>Jul 10 18:21:06 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{b40743ba-2121-4b7a-a6f1-fb12651476ac}"
>Jul 10 18:21:06 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{b40743ba-2121-4b7a-a6f1-fb12651476ac}"
>Jul 10 18:21:06 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{b40743ba-2121-4b7a-a6f1-fb12651476ac}"
>Jul 10 18:28:27 artemis kwin_wayland[10683]: kwin_libinput: Libinput: event8  - BY Tech Gaming Keyboard: client bug: event processing lagging behind by 29ms, your system is too slow
>Jul 10 18:29:56 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{4564ccf0-8721-4ceb-b9c8-15cce477609a}"
>Jul 10 18:29:56 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{4564ccf0-8721-4ceb-b9c8-15cce477609a}"
>Jul 10 18:29:56 artemis kwin_wayland[10683]: kwin_core: Could not find window with uuid "{4564ccf0-8721-4ceb-b9c8-15cce477609a}"
Comment 2 Danilo 2022-07-11 01:30:48 UTC
Created attachment 150529 [details]
kwin logs and drm logs
Comment 3 Zamundaaa 2022-07-11 13:18:24 UTC
The only suspicious thing I find in those logs is
> DM: Failed to update backlight on eDP[0]
but that's about the internal display

Can you add
> QT_LOGGING_RULES="kwin_*.debug=true"
to /etc/environment, reboot, reproduce the issue again and then upload the new kwin log?
Comment 4 Danilo 2022-07-11 21:58:05 UTC
Hi. Thanks for answering. It might be failed to update the backlight of my internal display because it was turned off. Ive attached the output of `journalctl --boot 0 | grep kwin_wayland` with `QT_LOGGING_RULES="kwin_*.debug=true"` added to /etc/environment.
Comment 5 Danilo 2022-07-11 21:59:21 UTC
Created attachment 150544 [details]
`journalctl --boot 0 | grep kwin_wayland` with `QT_LOGGING_RULES="kwin_*.debug=true"`
Comment 6 Danilo 2022-07-11 22:44:00 UTC
One very curious thing is that the monitor will not "turn off" while the little VLC icon bouncing beside my mouse cursor (Kde's way of indicating something is loading) doesn't go away. The it goes away AND the video is fullscreen AND the menu with the progress bar disappears, then I can observe the bug
Comment 7 Danilo 2022-07-11 22:45:15 UTC
I'm sorry, let me rewrite my last comment.
One very curious thing is that the monitor will not "turn off" while the little VLC icon bouncing beside my mouse cursor (Kde's way of indicating something is loading) doesn't go away. When the bouncing icon goes away AND the video is fullscreen AND the menu with the progress bar disappears, then I can observe the bug
Comment 8 Zamundaaa 2022-07-12 08:36:06 UTC
ok, that log has nothing of interest in it as well. As far as KWin knows, everything is working fine.

(In reply to Danilo from comment #7)
> One very curious thing is that the monitor will not "turn off" while the
> little VLC icon bouncing beside my mouse cursor (Kde's way of indicating
> something is loading) doesn't go away. When the bouncing icon goes away AND
> the video is fullscreen AND the menu with the progress bar disappears, then
> I can observe the bug
That's because this is about direct scanout; it's an optimization that (currently) only works when there is only a single unobstructed fullscreen window, and somehow causes problems for you.

We're almost certainly looking at a driver bug. Can you test a different compositor and see if that also breaks? The simplest to test and where direct scanout should be guaranteed is Weston - after you install it, you can select it on the bottom left of the login screen as an alternative session
Comment 9 Danilo 2022-07-12 17:56:49 UTC
Trying to open VLC in weston I got this:

VLC media player 3.0.17.4 Vetinari (revision 3.0.13-8-g41878ff4f2)
[000056171f2669d0] main interface error: no suitable interface module
[000056171f0f3430] main libvlc error: interface "globalhotkeys,none" initializat
ion failed
[000056171f0f3430] main libvlc: Running vlc with the default interface. Use 'cvl
c' to use vlc without interface.
[000056171f206bb0] main audio output error: too low audio sample frequency (0)
[00007f61d992d0c0] main decoder error: failed to create audio output
[000056171f206bb0] vlcpulse audio output error: digital pass-through stream conn
ection failure: Input/Output error
[000056171f206bb0] main audio output error: module not functional
[00007f61d992d0c0] main decoder error: failed to create audio output
Segmentation fault (core dumped)

That's not a problem though, because as I said, VLC is not the only video player in which the problem happens, so I could open Celluloid and the problem did not occur in Weston. If it is any useful, I had already tried gnome and didn't have this problem in it. That's why I thought if might be something in KDE
Comment 10 Zamundaaa 2022-07-16 15:33:34 UTC
Can you test in KWin again with these environment variables set one by one?
> KWIN_DRM_NO_DIRECT_SCANOUT=1
> KWIN_DRM_USE_MODIFIERS=0
> KWIN_DRM_PREFER_COLOR_DEPTH=24
So put one in /etc/environment, reboot, see if it works, remove it again and use the next one, reboot, etc
Comment 11 Danilo 2022-07-19 19:47:18 UTC
I couldn't notice anything different with any of them. The problem still occurs
Comment 12 Zamundaaa 2022-07-23 12:10:22 UTC
Are you certain that you applied them correctly? KWIN_DRM_NO_DIRECT_SCANOUT=1 should 100% work around this.
You can verify it by executing
> echo $KWIN_DRM_NO_DIRECT_SCANOUT
Comment 13 Danilo 2022-07-24 01:49:42 UTC
The problem started to bother me since I wanted to watch a show (was also happening with full-screen games), so I distro-hopped to Ubuntu. I can't tell you I'm 100% sure I'd applied them correctly, but now I can't test it anymore. Thanks for your help.
Comment 14 Danilo 2022-07-24 12:34:13 UTC
Went back to arch, tested KWIN_DRM_NO_DIRECT_SCANOUT=1, echoed it and recieved 1 as response. Problem still occurs. Upon reinstalling Arch, I noticed the problem wasn't occurring in wayland until I hopped to X11 to set a custom shortcut (Custom shortcuts tab don't show up in Wayland). After setting the shortcut, logging out of X11 and going back to Wayland, the problem returned
Comment 15 Matej Starc 2022-08-06 18:01:47 UTC
I am experiencing a similar bug (bug 456997). I also noticed that it happens when I go into fullscreen in mincraft aswell. The same does not happen when using a native qt/gtk app which probably means this is a problem with xwayland.
Comment 16 mensh123 2024-05-18 17:35:17 UTC
I am experiencing similar issues on Fedora 40, but the bug just appears randomly (sometimes on full screen entry and other times on full screen exit (the screen goes fully black in both cases).
Firefox and VLC seem to trigger this bug on full screen exit with a high likelyhood, especially when compared to other programs like Dragon Player. I should also note that the bug tends to often times repeat: If the screen turns black it is more likely for it to turn black on the next full screen toggle than if it doesn't turn black. This applies especially well to VLC.

Versions: Plasma 6.0.4, KWin 6.0.4, QT 6.7.0
Comment 17 Zamundaaa 2024-05-22 12:48:30 UTC
*** Bug 456997 has been marked as a duplicate of this bug. ***
Comment 18 Zamundaaa 2024-05-23 14:22:11 UTC
I wonder if this might be similar to bug 487208. Do you have adaptive sync enabled, and if so, does disabling it change anything?
Comment 19 mensh123 2024-05-23 15:07:52 UTC
(In reply to Zamundaaa from comment #18)
> I wonder if this might be similar to bug 487208. Do you have adaptive sync
> enabled, and if so, does disabling it change anything?

It appears to have helped in my case, but I can't speak for anyone else. Please note that I just posted to this bug because it involved black screens in fullscreen mode so the issue I had may honestly be completely unrelated.
Comment 20 Bug Janitor Service 2024-06-07 03:46:08 UTC
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Comment 21 Bug Janitor Service 2024-06-22 03:47:55 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
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