Black screen + mouse cursor after unlocking with light-lock + i3

diogobaeder · Yesterday 13:37:24

Hi folks,

I'm having an issue on my desktop computer where I lock my screen with "loginctl lock-session" (or "dm-tool lock", or "light-locker-command -l" - it's always the same behavior) and, when I unlock it through the LightDM screen, I'm sent to either a black screen with the mouse cursor working (but unable to operate the desktop) or a frozen screen of the desktop. Usually I just restart i3 with my key binding and it's fine, I get the desktop back, but sometimes it doesn't work so I have to enter another TTY and run "systemctl restart lightdm.service", which is rather annoying since it starts my desktop from scratch (in terms of state).

Here's the stuff I'm using (i3lock is installed, but I'm not currently using it - and uninstalling it didn't fix the issue):

$ pacman -Qi lightdm light-locker xss-lock i3-wm i3lock nvidia systemd | grep -E '(Nome|Vers)'
Nome                 : lightdm
Versão               : 1:1.32.0-6
Nome                 : light-locker
Versão               : 1.9.0-5
Nome                 : xss-lock
Versão               : 0.3.0.r30.gac39fdc-1
Nome                 : i3-wm
Versão               : 4.24-1
Nome                 : i3lock
Versão               : 2.15-2
Nome                 : nvidia
Versão               : 570.133.07-5
Nome                 : systemd
Versão               : 257.5-1

$ uname -a
Linux diogobaeder-desktop 6.14.2-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 10 Apr 2025 18:43:59 +0000 x86_64 GNU/Linux

$ sudo lsmod | grep -i nvidia
nvidia_drm            135168  12
drm_ttm_helper         16384  2 nvidia_drm
nvidia_uvm           3792896  0
nvidia_modeset       1830912  17 nvidia_drm
video                  81920  1 nvidia_modeset
nvidia              97095680  215 nvidia_uvm,nvidia_modeset

More info about light-locker:

$ light-locker --debug
[gs_debug_init] ../light-locker/src/gs-debug.c:106 (10:29:52):	 Debugging enabled
[main] ../light-locker/src/light-locker.c:138 (10:29:52):	 initializing light-locker 1.9.0
[main] ../light-locker/src/light-locker.c:139 (10:29:52):	 Platform:
gtk:        3
systemd:    yes
UPower:     yes
[main] ../light-locker/src/light-locker.c:155 (10:29:52):	 Features:
lock-after-screensaver: yes
late-locking:           yes
lock-on-suspend:        yes
lock-on-lid:            yes
settings backend:       GSETTINGS
[main] ../light-locker/src/light-locker.c:188 (10:29:52):	 lock after screensaver 5
[main] ../light-locker/src/light-locker.c:189 (10:29:52):	 late locking 1
[main] ../light-locker/src/light-locker.c:190 (10:29:52):	 lock on suspend 1
[main] ../light-locker/src/light-locker.c:191 (10:29:52):	 lock on lid 1
[main] ../light-locker/src/light-locker.c:192 (10:29:52):	 idle hint 0
[init_session_id] ../light-locker/src/gs-listener-dbus.c:2234 (10:29:52):	 Got session-id: /org/freedesktop/login1/session/_36
[find_graphical_session] ../light-locker/src/gs-listener-dbus.c:2104 (10:29:52):	 Finding a graphical session for user 1000
[init_session_id] ../light-locker/src/gs-listener-dbus.c:2245 (10:29:52):	 Got sd-session-id: /org/freedesktop/login1/session/_36
[init_seat_path] ../light-locker/src/gs-listener-dbus.c:2326 (10:29:52):	 Got seat: /org/freedesktop/DisplayManager/Seat0
[gs_listener_delay_suspend] ../light-locker/src/gs-listener-dbus.c:414 (10:29:52):	 Delay suspend

** (light-locker:32081): WARNING **: 10:29:52.884: screensaver already running in this session

I'm running almost the same stuff on my laptop though, and there I don't have the same issue.

Any ideas or hints for what I can do to fix this? I feel like I'm doing something wrong, or configured something wrong, but I can't figure out what.

Thanks in advance!

diogobaeder · Yesterday 13:48:09

Forgot to include these, sorry:

$ pacman -Qi lightdm-gtk-greeter lightdm-gtk-greeter-settings | grep -E '(Nome|Vers)'
Nome                 : lightdm-gtk-greeter
Versão               : 1:2.0.9-1
Nome                 : lightdm-gtk-greeter-settings
Versão               : 1.2.3-3

diogobaeder · Yesterday 14:40:13

I tried switching to lightdm-slick-greeter, but it didn't fix the issue.

diogobaeder · Yesterday 17:01:05

I just tried it again a few times right after booting my computer, and these were my results:

1. It didn't go to the black page on the first unlock
2. It went to the black page on the second unlock, but after a few seconds waiting the normal screen showed up
3. On the third attempt, it showed up just fine after unlocking

So this issue seems to be related to timing, from some tool somewhere.

diogobaeder · Yesterday 23:20:50

I ended up switching to i3lock, which is not my favorite, but it does the job well. If I can find a solution to using light-locker, though, I'd rather use it instead.

Arch Linux

#1 Yesterday 13:37:24

Black screen + mouse cursor after unlocking with light-lock + i3

#2 Yesterday 13:48:09

Re: Black screen + mouse cursor after unlocking with light-lock + i3

#3 Yesterday 14:40:13

Re: Black screen + mouse cursor after unlocking with light-lock + i3

#4 Yesterday 17:01:05

Re: Black screen + mouse cursor after unlocking with light-lock + i3

#5 Yesterday 23:20:50

Re: Black screen + mouse cursor after unlocking with light-lock + i3

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