Bug 442015

SUMMARY

Since about a week now (after running some system updates) my Notebooks screen will suddenly turn black after something in between 1 min after plasma has completely started (rare) and more often something between 10 min and 30 min. The backlight is still on, I can adjust the brightness. Moving the mouse after some idle time makes the screen turn on (changes from pitch black to backlit black). I can ssh in and run commands. Videos in firefox continue playing and can be paused/started by mouse clicks. I can often press the power button and then enter and it will shutdown. Plymouth will shortly show the Kde neon logo before the computer turns off.

Pressing Shift+Alt+F12 does nothing.

When I ssh in, kwin_x11 is still running.


STEPS TO REPRODUCE
1. Start Notebook
2. Do anything or nothing
3. empty/black screen

OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
plasma-workspace 4:5.22.4-0xneon+20.04+focal+release+build42    amd64        Plasma Workspace for KF5
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: libkf5windowsystem-dev  5.85.0-0xneon+20.04+focal+release+build22
Qt Version: libqt5core5a:amd64  5.15.2+p20.04+tunstable+git20210826.0127-0

ADDITIONAL INFORMATION

replacing kwin via ssh:
DISPLAY=:0 kwin_x11 --replace
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5127:46: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5129:48: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5131:48: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5135:47: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5137:46: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5145:48: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5149:46: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5151:46: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5155:45: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: /usr/share/X11/locale/en_US.UTF-8/Compose:5158:46: this compose sequence is a duplicate of another; skipping line
kwin_xkbcommon: XKB: inet:224:50: unrecognized keysym "XF86FullScreen"
qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 6184, resource id: 29360235, major code: 18 (ChangeProperty), minor code: 0
OpenGL vendor string:                   Intel
OpenGL renderer string:                 Mesa Intel(R) HD Graphics 620 (KBL GT2)
OpenGL version string:                  4.6 (Compatibility Profile) Mesa 21.0.3
OpenGL shading language version string: 4.60
Driver:                                 Intel
GPU class:                              Kaby Lake
OpenGL version:                         4.6
GLSL version:                           4.60
Mesa version:                           21.0.3
X server version:                       1.20.11
Linux kernel version:                   5.11
Requires strict binding:                yes
GLSL shaders:                           yes
Texture NPOT support:                   yes
Virtual Machine:                        no
kwin_core: XCB error: 10 (BadAccess), sequence: 6327, resource id: 1956, major code: 142 (Composite), minor code: 2 (RedirectSubwindows)

but nothing happens

in journalctl I can see some of these when the screen first goes blank:
Sep 04 22:26:15 sisBook kwin_x11[1182]: kwin_core: XCB error: 3 (BadWindow), sequence: 4545, resource id: 14710390, major code: 129 (SHAPE), minor code: 8 (GetRectangles)
Sep 04 22:26:18 sisBook plasmashell[1264]: trying to show an empty dialog
Sep 04 22:26:19 sisBook kwin_x11[1182]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 14198, resource id: 41943045, major code: 18 (ChangeProperty), minor code: 0
Sep 04 22:26:19 sisBook systemd[1013]: Started Discover - Programmverwaltung.
Sep 04 22:26:19 sisBook kwin_x11[1182]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 14203, resource id: 41943046, major code: 18 (ChangeProperty), minor code: 0

kwin support info (after black and replacing via ssh): https://invent.kde.org/-/snippets/1835

nothing appears in dmesg