Bug#972417: xfce4-power-manager: System left idle => 'display power management' auto-locks session => no X session or lightdm greeter
Package: xfce4-power-manager
Version: 1.6.1-1
Severity: grave
Dear Maintainer,
[ Bug description ]
Bug happens when the screen auto-locks due to user inactivity. Then the screen switches off.
To easily test that, set following to 1 min or so
Xfce menu Applications -> Settings -> Power Manager -> Display -> 'Switch off after'
After such auto-lock, it appears not possible to get back the X session anymore.
Because
- by moving mouse or typing on keyboard the screen does not wake up. It stays off, black.
- with Ctrl+Alt-F7 one gets
This session is locked
You’ll be redirected to the unlock
dialog automatically in a few seconds
but after waiting a few seconds the screen switches off again.
=> no way to get to the lightdm greeter.
In both cases: not possible to get back the running X session anymore.
[ Guilty package ]
Bug is _not_ triggered when user locks computer by doing any of
Ctrl-Alt-Del
xflock4 (in fact = Ctrl-Alt-Del)
light-locker-command --lock
dm-tool lock
As moving the mouse or typing on keyboard wakes up the screen and display the lightdm greeter.
=> I filled this bug against xfce4-power-manager
But I have no clue whether xfce4-power-manager
- processes the locking completely by itself ?
- just prepares locking, like deactivating keyboard/mouse? and then trigger like light-locker-command --lock...
- only asks another package to do the full locking procedure.
[ Workaround if locked out ]
Following allows to get the running X session back:
switch to tty1 by Ctrl+Alt+F1
funny note: sometimes the mouse pointer is displayed on top of tty1 (moving the mouse does not move pointer).
log as root
run
loginctl unlock-sessions
switch back to X by Alt+F7
[ Related packages version ]
All below are up to date Buster packages
dpkg -l "xfce4-power-manager" "lightdm*" "light-locker" "xfce4-session"
||/ Name Version
ii light-locker 1.8.0-3
ii lightdm 1.26.0-4
un lightdm-greeter <none>
ii lightdm-gtk-greeter 2.0.6-1
ii xfce4-power-manager 1.6.1-1
ii xfce4-session 4.12.1-6
Bug occurred under (at least) both kernels:
linux-image-4.19.0-11-amd64-unsigned 4.19.146-1
linux-image-5.8.0-0.bpo.2-amd64 5.8.10-1~bpo10+1
I tried Bullseye/Sid version: 1.6.6-1 by backporting it
Bug still occurs.
dpkg -l "xfce4-power-manager*" "lightdm*" "light-locker*" "xfce4-session*" "libxfce4ui*"
||/ Name Version
ii libxfce4ui-1-0:amd64 4.12.1-3
ii libxfce4ui-1-dev:amd64 4.12.1-3
ii libxfce4ui-2-0:amd64 4.14.1-1~bpo10+1
ii libxfce4ui-2-dev:amd64 4.14.1-1~bpo10+1
ii libxfce4ui-build-deps 4.14.1-1~bpo10+1
ii libxfce4ui-common 4.12.1-3
ii libxfce4ui-utils 4.12.1-3
ii light-locker 1.8.0-3
ii lightdm 1.26.0-4
un lightdm-greeter <none>
ii lightdm-gtk-greeter 2.0.6-1
ii xfce4-power-manager 1.6.6-1~bpo10+1
ii xfce4-power-manager-data 1.6.6-1~bpo10+1
ii xfce4-power-manager-plugins 1.6.6-1~bpo10+1
ii xfce4-session 4.12.1-6
[ Severity justification ]
As described in several reports, users usually handle the black screen by
restarting the system
or if users has root access:
killall Xorg => restarts X session
killall lightdm => restarts X session
killall light-locker => X sessions won't lock anymore
All except last cause loss of unsaved data, last causes a security concern.
=> severity = grave
Also this bug gives a bad image to the user:
- 'system crashed'
- wondering what is the cause:
- is my graphic card not properly waking up ?
- or a bug in kernel ?
- or Xorg ?
- or light-locker ?
...
Thus they are probably numerous of open bugs that could be closed by fixing this bug.
[ Bugs reported against other packages, & that seem linked to this bug ]
Bugs in source package light-locker
#906902 System left idle makes system freeze
#870641 light-locker, lightdm: screen stays off after resume
and all the merged one:
805711, 846278, 868087, 908329, 922095, 929461, 929834, 931555
#835461 light-locker breaks suspend/resume with nvidia legacy 340 drivers
Bugs in source package lightdm
#867620 lightdm unlock screen randomly doesn't appear
Kind regards,
Franck Richter
-- System Information:
Debian Release: 10.6
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'proposed-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 5.8.0-0.bpo.2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages xfce4-power-manager depends on:
ii libc6 2.28-10
ii libcairo2 1.16.0-4
ii libgdk-pixbuf2.0-0 2.38.1+dfsg-1
ii libglib2.0-0 2.58.3-2+deb10u2
ii libgtk-3-0 3.24.5-1
ii libnotify4 0.7.7-4
ii libpango-1.0-0 1.42.4-8~deb10u1
ii libpangocairo-1.0-0 1.42.4-8~deb10u1
ii libupower-glib3 0.99.10-1
ii libx11-6 2:1.6.7-1+deb10u1
ii libxext6 2:1.3.3-1+b2
ii libxfce4ui-2-0 4.14.1-1~bpo10+1
ii libxfce4util7 4.12.1-3
ii libxfconf-0-2 4.12.1-1
ii libxrandr2 2:1.5.1-1
ii upower 0.99.10-1
ii xfce4-power-manager-data 1.6.6-1~bpo10+1
Versions of packages xfce4-power-manager recommends:
ii libpam-systemd 241-7~deb10u4
ii xfce4-power-manager-plugins 1.6.6-1~bpo10+1
xfce4-power-manager suggests no packages.
-- no debconf information
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