(partially solved, will update when completed) Please help with an xfce/powerup bug: black screen after suspend/hibernate
MX Linux, Xfce 4.18
Closing the laptop lid suspends the system, opening it resumes it, but the screen is black. I'm guessing it's related to powerup because suspending through the logout menu and systemctl suspend both work as expected. When it's black, switching to a different tty works, as well as C-M-Backspace to logout.
Same results with both lightdm and sddm, when replacing suspend with hibernate, and I've tried a few solutions like disabling lock on sleep.
Seems like this issue has been around for years, but had a whole bunch of different causes since every other thread has a different solution.
Since that bug seems related to the X server somehow, I wonder if your monitor is showing black or actually off/standby (as in backlight off)?
If it's the backlight, maybe it's related to DPMS (monitor power management), and you can jolt it back to life with something like
xset dpms force on
after waking up. Or maybe disable DPMS completely and see if that changes anything.
It would also be interesting to know if this problem also happens outside of XFCE. If you just use (say) openbox (which I don't think does any power management or DPMS stuff by itself), does that work?
I wonder if your monitor is showing black or actually off/standby (as in backlight off)?
It actually starts, and then turns off. I didn't notice it before you drew my attention.
The command doesn't do anything, but I was able to type sudo reboot and it rebooted.
It would also be interesting to know if this problem also happens outside of XFCE
I can't install anything new, but I just tried starting power manager in i3 and using it to go to standby when i close the lid. It woke up 10 times in a row without an issue. So it's most likely a purely xfce issue that's been around for like a decade in different forms.
It actually starts, and then turns off. I didn’t notice it before you drew my attention.
That does sound like DPMS ("vesa display power management signaling") shenanigans though.
Maybe you can disable XFCE's display power management stuff completely? Systemd's logind (/etc/systemd/logind.conf) can do (and does by default I think) suspend on lid-close without any window manager involvement at all, works fine with i3 here. So disabling XFCE's stuff probably "only" messes with your monitor not going standby after a while, and you can maybe use xset or xscreensaver and set this by hand (after making sure it's actually properly disabled in XFCE, so XFCE doesn't override that stuff).
Found this about how to stop xfce4-power-manager and disable DPMS:
xfce4-power-manager -q
xset -dpms
Try doing that and see if lid close works afterwards.
I found a different solution: trigger an xrandr config. I'm leaving automating it for tomorrow.
The funniest thing is that I was trying to help out some other lemmy user fix their own xrandr issues, and accidentally came across a thread mentioning it when I went back to fixing my own.
I found it because you pointed out the monitor might be turning off. Changed search terms and found the recommendation in a Reddit thread. The full solution wasn't great though.