Unable to configure lightdm

Hi,

I’m hoping for my Jetson TK1 to eventually be able to boot into a single-application (i.e. a kiosk-like mode) using lightdm and xsessions. I tinkered around with some xsession profiles, but I decided to take it one step at a time and simply change the desktop environment first. However, I am having issues with lightdm not changing the default session. I am using Ubuntu 14.04.

To start, I’ve been trying to the default session from ubuntu.desktop to xfce.desktop by changing the lightdm configurations in the /etc/lightdm/ folder.

In the /usr/share/xsessions directory I have

-rw-r--r--   1 root root   216 Jan  1  2000 gnome.desktop
-rw-r--r--   1 root root  4294 Dec 11 04:57 ubuntu.desktop
-rw-r--r--   1 root root   215 Dec 11 04:04 ubuntuold.desktop
-rw-r--r--   1 root root  4294 Mar 21  2014 xfce.desktop

First I made the lightdm.conf file so that I could load the xfce.desktop session by default. Below is the lightdm.conf file.

[SeatDefaults]
user-session=xfce
autologin-user=ubuntu
autologin-user-timeout=0

After rebooting the Jetson, the system still logs into the normal gnome/unity desktop. From looking at the lightdm log below, it seems that there is no change in the lightdm settings (line 44 is the culprit, and should mention that it is using xfce rather than gnome/unity).

ubuntu@tegra-ubuntu:~$ sudo more /var/log/lightdm/lightdm.log
[sudo] password for ubuntu: 
[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.10.1, UID=0 PID=823
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registered seat module xlocal
[+0.01s] DEBUG: Registered seat module xremote
[+0.01s] DEBUG: Registered seat module unity
[+0.01s] DEBUG: Registered seat module surfaceflinger
[+0.02s] DEBUG: Adding default seat
[+0.02s] DEBUG: Seat: Starting
[+0.02s] DEBUG: Seat: Creating user session
[+0.11s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.11s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.18s] DEBUG: Seat: Creating display server of type x
[+0.19s] DEBUG: Quitting Plymouth
[+0.22s] DEBUG: Using VT 7
[+0.22s] DEBUG: Seat: Starting local X display on VT 7
[+0.22s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.22s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.22s] DEBUG: DisplayServer x-0: Launching X Server
[+0.22s] DEBUG: Launching process 916: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -
novtswitch
[+0.22s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.22s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.22s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+1.31s] DEBUG: Got signal 10 from process 916
[+1.31s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+1.31s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+1.32s] DEBUG: Seat: Display server ready, starting session authentication
[+1.32s] DEBUG: Session pid=1107: Started with service 'lightdm-autologin', username 'ubuntu'
[+1.42s] DEBUG: Session pid=1107: Authentication complete with return value 0: Success
[+1.42s] DEBUG: Seat: Session authenticated, running command
[+1.42s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+1.43s] DEBUG: Session pid=1107: Running command /usr/sbin/lightdm-session gnome-session  --session=ubuntu
[+1.43s] DEBUG: Creating shared data directory /var/lib/lightdm-data/ubuntu
[+1.43s] DEBUG: Session pid=1107: Logging to .xsession-errors
[+1.45s] DEBUG: Activating VT 7
[+1.45s] DEBUG: Activating login1 session /org/freedesktop/login1/session/c1
[+2.62s] DEBUG: User /org/freedesktop/Accounts/User1000 changed
[+89.71s] DEBUG: User /org/freedesktop/Accounts/User1000 changed

Another thing I tried is by overwriting the ubuntu.desktop xsession as the desired xfce.desktop xsession. Rebooting the jetson with this configuration, the Jetson boots into a blank/black screen. The lightdm logs are below, and line 43 shows that the xfce session is being started.

ubuntu@tegra-ubuntu:/var/log/lightdm$ sudo more lightdm.log
[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.10.1, UID=0 PID=819
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registered seat module xlocal
[+0.01s] DEBUG: Registered seat module xremote
[+0.01s] DEBUG: Registered seat module unity
[+0.01s] DEBUG: Registered seat module surfaceflinger
[+0.02s] DEBUG: Adding default seat
[+0.02s] DEBUG: Seat: Starting
[+0.02s] DEBUG: Seat: Creating user session
[+0.10s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.10s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.18s] DEBUG: Seat: Creating display server of type x
[+0.19s] DEBUG: Quitting Plymouth
[+0.22s] DEBUG: Using VT 7
[+0.22s] DEBUG: Seat: Starting local X display on VT 7
[+0.22s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.22s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.22s] DEBUG: DisplayServer x-0: Launching X Server
[+0.22s] DEBUG: Launching process 910: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -
novtswitch
[+0.22s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.22s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.22s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+1.44s] DEBUG: Got signal 10 from process 910
[+1.44s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+1.44s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+1.45s] DEBUG: Seat: Display server ready, starting session authentication
[+1.45s] DEBUG: Session pid=1109: Started with service 'lightdm-autologin', username 'ubuntu'
[+1.52s] DEBUG: Session pid=1109: Authentication complete with return value 0: Success
[+1.52s] DEBUG: Seat: Session authenticated, running command
[+1.52s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+1.53s] DEBUG: Session pid=1109: Running command /usr/sbin/lightdm-session startxfce4
[+1.53s] DEBUG: Creating shared data directory /var/lib/lightdm-data/ubuntu
[+1.53s] DEBUG: Session pid=1109: Logging to .xsession-errors
[+1.55s] DEBUG: Activating VT 7
[+1.55s] DEBUG: Activating login1 session /org/freedesktop/login1/session/c1
[+2.75s] DEBUG: User /org/freedesktop/Accounts/User1000 changed
[+53.87s] DEBUG: User /org/freedesktop/Accounts/User1000 changed
[+123.14s] DEBUG: User /org/freedesktop/Accounts/User1000 changed

I have tried to loading into the gnome.desktop with similar results. I have also tried editing the /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf, from the default user-session ubuntu, to xfce. Rebooting the jetson, the changes to the 50-ubuntu.conf file seemed to have no effect on the default session.

Here’a a link to a forum post where the user has done what I am trying to achieve, but with success :/

https://devtalk.nvidia.com/default/topic/785551/embedded-systems/my-jetson-focused-linux-tips-and-tricks/

Thanks,
Tom

Hi Tom, the package manager should take care of any issues when installing xfce. xfce installed on my system without issues, all that was required was “sudo apt-get install xfce4”

As for logging in automatically under xfce, this seemed to work for me:

  1. Create /etc/lightdm/lightdm.conf
  2. Add the following lines to the lightdm.conf file:

    [SeatDefaults]
    user-session=xfce4
    autologin-user=ubuntu

  3. Save the file and reboot.

Hopefully you should have similar results.

Hi

This may or may not help.

To get xfce to work, I stripped out the ubuntu GUI and loaded everything that just xfce needed.
I noted that the display manager that xfce is NOT lightdm and is not supported any more.

I forget where I got the instructions to do it. I do remember that the instructions included doing
lots of
sudo apt-get remove (also some ‘purge’ )
to remove the Ubuntu GUI.

Then I installed xfce from scratch.

“I’m hoping for my Jetson TK1 to eventually be able to boot into a single-application (i.e. a kiosk-like mode)”
Why fiddle with the ubuntu GUI, why dont you just concentrate on the kiosk application.
I think there are lots of them around and I would think that they deal with the boot up/login thing as part of the package.
That was definitely the case with Sunray Kiosk from Sun