18.04: Even with WaylandEnable=false gdm3 and lightdm only load sometimes

[Dáire Fagan]

I have a GTX970, using nvidia-driver-415, and the following is what happens with each greeter.

lightdm:


Every third or so login instead of the greeter I would see a blinking underscore top left of an otherwise black screen. When I was able to login, Ubuntu would tell me that a System Program problem has been detected and prompted me to report the error, which I have been doing. /var/crash/ then would contain a newly generated _usr_lib_xorg_Xorg.0.crash file. I have copied this file to my home directory, but I am still unable to open it with a text editor to investigate? Searching for the file online I found a post where someone explained their issue was with lightdm (I appreciate my issue could be something else), but as I was using lightdm, I thought I would try gdm3 again.


gdm3:


After my recent 16.04/16.10 installs, when I use gdm3, even with WaylandEnable=false uncommented in /etc/gdm3/custom.conf, I could never login, instead of the the greeter I would see either a black screen or graphic distortion like a black screen with some pink lines across the top, and I was only able to login setting nomodeset.

Despite this, a few days ago I tried gdm3 again, so I input the following:


sudo apt-get install gdm3
sudo dpkg-reconfigure gdm3



This seemed to work - kind of, for the first few days I could boot most of the time. I have quiet splash permanently removed from my boot options, and boot was sometimes hanging on Started NVIDIA Persistence Daemon as below:

282099

Then this morning, I attempted to boot but 4 or 5 times the system stopped booting at the following two different lines, and I could only login with nomodeset:

282100282101

I appreciate one of those stopped after doing something with my encrypted driver liberty - but nomodeset immediately resolved the issue next boot, so this issue is graphics related. I believe it is the same issue that was displaying Started NVIDIA Persistence Daemonu up until this morning. Searching for this online though, the only advice I found was to either uncomment WaylandEnable=false or using lightdm instead, and I have tried both. I am happy to use either display manager, I just want one of them to be stable and load reliably :)

How can I begin to resolve this please?

[Dáire Fagan]

lightdm

lightdm:
Installed: 1.26.0-0ubuntu1

Same lightdm issue again today, instead of seeing the greeter I see a black screen, with a single white underscore top left, and the screen flashes every second or so.

I could not get to a shell using ctrl + alt + f3/f4/f5, so I rebooted, logged in again using nomodeset, and from a terminal checked the permissions of the following:


-rw------- 1 dusf dusf 56 Jan 7 17:38 .Xauthority
-rw------- 1 dusf dusf 15886 Jan 7 17:38 .ICEauthority

drwxrwxrwt 16 root root 4096 Jan 7 17:45 /tmp


Then input:


sudo chown dusf:dusf .Xauthority
sudo chown dusf:dusf .ICEauthority
sudo chmod a+wt /tmp

I rebooted and I was able to login, but Ubuntu has just reported another error:

282116

I expect the crash after login is connected to whatever is preventing the greeter loading. I used apport to put the files in a directory, and then I zipped them to upload here but the file exceeds the maximum upload size. Is there no easier way to read what the crash log is saying, and get this fixed?

[Dáire Fagan]

lightdm

Same issue again on rebooting, this time rebooted with nomodeset, and when I saw the greeter I switched to a shell and input:


sudo dpkg-reconfigure lightdm

...selected lightdm, and then rebooted.

Able to login normally, but Ubuntu warns me again of System Program problem detected.

In:


cat .xsession-errors

the last line reads:


_=/usr/bin/dbus-update-activation-environment

This is possibly related, as an underscore is what I see instead of the greeter?

[corradoventu]

To open a .crash file in /var/crash you must be authorized to group whoopsie

sudo adduser xxx whoopsie
where xxx is your userid
you may check your groups with:
corrado@corrado-p6-dd-1227:~$ groups
corrado adm cdrom sudo dip plugdev lpadmin whoopsie sambashare
corrado@corrado-p6-dd-1227:~$

warning: you will have woopsie group only at next login

[Dáire Fagan]

To open a .crash file in /var/crash you must be authorized to group whoopsie

sudo adduser xxx whoopsie
where xxx is your userid
you may check your groups with:
corrado@corrado-p6-dd-1227:~$ groups
corrado adm cdrom sudo dip plugdev lpadmin whoopsie sambashare
corrado@corrado-p6-dd-1227:~$

warning: you will have woopsie group only at next login

Done, thank you for that. I will upload the crash log on the next System Program problem detected.

Is there somewhere I can view a log from when my system attempted to load the greeter unsuccessfully, after I login immediately afterward using a workaround?

lightdm

Same issue again today:

282132


mv .Xauthority .Xauthority.bak

Greeter loaded successfully on next boot.

[Dáire Fagan]

lightdm

Same black screen again on boot, current workaround:


sudo apt-get purge lightdmsudo apt-get install --reinstall lightdm
sudo apt-get install gnome
reboot


I have logged in twice since, and there has been no System Program problem detected just yet...

[Dáire Fagan]

lightdm

So after a sudo apt upgrade a few days ago with the same issue recurring I used nomodeset, switched to a TTY and input the following:


sudo apt upgradesudo apt purge lightdm
sudo apt purge gnome
sudo apt purge nvidia*
sudo apt remove nvidia-driver-415
reboot
sudo apt purge nvidia-*
sudo apt install nvidia-415
sudo apt install nvidia-driver-415
reboot
sudo apt purge xorg-* xserver-xorg
sudo apt install xorg xserver-xorg
sudo dpkg-reconfigure xorg
sudo apt purge ubuntu-gnome-desktop
sudo apt purge gnome-desktop-environment
apt install ubuntu-gnome-desktop
sudo apt install ubuntu-gnome-desktop
sudo apt purge lightdm
sudo apt install --reinstall lightdm


I was able to access the greeter and login in successfully then for a few days, but again this morning the same flashing underscore screen. After logging in using nomodeset, looking at my .bash_history, I can see the last two commands I input last night were:


sudo apt updatesudo apt upgrade

So I think it is possible that upset something with lightdm.

Perhaps there is something in the following logs that could shed some light on the issue?


cat /var/log/lightdm/lightdm.log

https://paste.ubuntu.com/p/wkfmNrrctG/


cat /var/log/kern.log

https://paste.ubuntu.com/p/g9bRKpMnxW/


cat .xsession-errors

https://paste.ubuntu.com/p/KhjrKYwmdj/

From some reading this morning, perhaps something could be done by adding an xrandr line to a config file? Some of the files people mention do not exist on my system, and people mention adding many different xrandr lines to many different files.

I am out of my depth here, could someone please advise?

[Dáire Fagan]

I am using 18.04, not 16.04.