[TUTORIAL] Make Log in Screen (LightDM) use same Display Properties as When Logged in

[mattlach]

Hey everyone,

I recently figured this one out, and figured I'd document it here for posterity.

If you are anything like me, you have multiple screens rotated in different directions which works fine once logged in, but your log-in screen is all messed up.

As an example, here is how I have my screens set up in Cinnamon:

A 20" 1600x1200 screen in portrait rotated counter clockwise on the left
A 43" 3840x2160 screen in lanscape in the center
Another 20" 1600x1200 screen in portrait rotated clockwise on the right.

Lets just say that on the system login screen (LightDM) the screens are not configured like this, and if you knock your mouse pointer off the center one, it can be surprisingly difficult to get it back, tilting your head sideways and trying to navigate the pointer to the right place.

It also looks cleaner if your login matches the layout you want, so here is how to achieve that.

1.) Configure your screens how you want them in the Display properties settings.

2.) Install and use arandr to create an xrandr string from your preferred layout.

Open a terminal and do the following:

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sudo apt update
sudo apt install arandr

Run arandr from the GUI menu:

You should see your screen layout as you have it configured.

If you are happy with it as is, then save it to an xrandr string:

Layout Menu -> Save As

Save it somewhere you know where it is, and name it something nice. I chose to put it on my Desktop and name it "lightdm_xrandr.sh"


3.) Prepare the file containing your xrandr string for use:

The file contained my somewhat semi-complicated xrandr string:

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#!/bin/sh
xrandr --output DisplayPort-0 --primary --mode 3840x2160 --pos 1200x0 --rotate normal --output DisplayPort-1 --mode 1600x1200 --pos 0x560 --rotate left --output DisplayPort-2 --off --output HDMI-A-0 --mode 1600x1200 --pos 5040x560 --rotate right

Unless you have the exact screen layout I do, yours will look different.

For good measure I decided to edit it and add an "exit 0" to the end. This is probably not necessary, but it is proper.

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sudo nano ~/Desktop/lightdm_xrandr.sh

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#!/bin/sh
xrandr --output DisplayPort-0 --primary --mode 3840x2160 --pos 1200x0 --rotate normal --output DisplayPort-1 --mode 1600x1200 --pos 0x560 --rotate left --output DisplayPort-2 --off --output HDMI-A-0 --mode 1600x1200 --pos 5040x560 --rotate right
exit 0

after saving, we should check to make sure it is executable. arandr seems to do this by default, but it doesn't hurt to check:

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# ls -l ~/Desktop/lightdm_xrandr.sh
-rwx------ 1 matt matt 263 Oct 22 23:38 lightdm_xrandr.sh

-rwx------ -> Read Write eXecute. Permissions are correct (in Mints default bash config the file should also be listed as green if it is executable)

If it is not executable you can make it so with the following command:

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chmod 700 ~/Desktop/lightdm_xrandr.sh

Then move this script to /etc/lightdm

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sudo mv ~/Desktop/lightdm_xrandr.sh /etc/lightdm/

So now we have a "script" that sets the proper screen orientation. Now we have to tell lightdm to execute it on startup.

4.) Tell lightdm to execute your xrandr string on boot:

First we have to find the config file. Since the file may differ by version or specific configuration, rather than tell you which file I edited, I will show you how to find yours, just in case yours is different.

Run lightdm --show-config to display the current configuration.

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# lightdm --show-config

   [Seat:*]
A  allow-guest=false
C  greeter-wrapper=/usr/lib/lightdm/lightdm-greeter-session
D  guest-wrapper=/usr/lib/lightdm/lightdm-guest-session
E  xserver-command=X -core
F  greeter-session=slick-greeter
G  user-session=cinnamon

   [LightDM]
B  backup-logs=false

Sources:
A  /usr/share/lightdm/lightdm.conf.d/50-disable-guest.conf
B  /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf
C  /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
D  /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
E  /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
F  /usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf
G  /etc/lightdm/lightdm.conf.d/70-linuxmint.conf

Look for a config file that says something about "slick greeter". In my case this was:
/usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf

Edit this file:

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# sudo nano /usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf

By default it should look like this:

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[Seat:*]
greeter-session=slick-greeter

Add this line between [Seat:*] and greeter-sessiion as follows:

greeter-setup-script=/etc/lightdm/lightdm_xrandr.sh

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[Seat:*]
greeter-setup-script=/etc/lightdm/lightdm_xrandr.sh
greeter-session=slick-greeter

Reboot. Your login screen should now be oriented the same as your desktop once logged in.

I hope this helps someone else.

[SMG]

I hope this helps someone else.

It did. I recommended your tutorial to someone with a slightly different issue and it worked for them .

[mattlach]

I hope this helps someone else.

It did. I recommended your tutorial to someone with a slightly different issue and it worked for them .

Nice! That makes spending the time on the write-up worth it!

[Mosfetwall]

@mattlach Thanks mate !

The login orientation of my second monitor was driving me insane .

[mattlach]

To update this a little.

I just upgraded from 20.2 to 20.3. IN doing so, the installer seems to have overwritten the slick greeter config file:

/usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf

Everything else seems to have been untouched, so after upgrading, if you just repeat the last step (adding the line to 90-slick-greeter.conf) everything should work again.

[AndyMH]

I do similar things - set display resolution on boot with xrandr. But:

In /etc/lightdm/lightdm.conf.d, I have a file 70-linuxmint.conf. Create a new file 71-linuxmint.conf, i.e. a higher number.

Content of 71-linuxmint.conf is:

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[SeatDefaults]
user-session=cinnamon
display-setup-script=/usr/bin/LGmonitor.bsh

It is pointing at a setup script to set the resolution on my monitor.

It does not get overwritten on an update.

the installer seems to have overwritten the slick greeter config file:

If you had created a /usr/share/lightdm/lightdm.conf.d/91-slick-greeter.conf it would not have been overwritten.

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xrandr --output DisplayPort-0 --primary --mode 3840x2160 --pos 1200x0 --rotate normal --output DisplayPort-1 --mode 1600x1200 --pos 0x560 --rotate left --output DisplayPort-2 --off --output HDMI-A-0 --mode 1600x1200 --pos 5040x560 --rotate right

It would be a wise move to wrap this statement in some if statements checking that the monitors are configured as the line expects. You could end up with a system with no graphical display if one or more of the ports are not connected. I know, I've made this mistake.

[mattlach]

I do similar things - set display resolution on boot with xrandr. But:

In /etc/lightdm/lightdm.conf.d, I have a file 70-linuxmint.conf. Create a new file 71-linuxmint.conf, i.e. a higher number.

Content of 71-linuxmint.conf is:

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[SeatDefaults]
user-session=cinnamon
display-setup-script=/usr/bin/LGmonitor.bsh

It is pointing at a setup script to set the resolution on my monitor.

It does not get overwritten on an update.

the installer seems to have overwritten the slick greeter config file:

If you had created a /usr/share/lightdm/lightdm.conf.d/91-slick-greeter.conf it would not have been overwritten.

Code: Select all

xrandr --output DisplayPort-0 --primary --mode 3840x2160 --pos 1200x0 --rotate normal --output DisplayPort-1 --mode 1600x1200 --pos 0x560 --rotate left --output DisplayPort-2 --off --output HDMI-A-0 --mode 1600x1200 --pos 5040x560 --rotate right

It would be a wise move to wrap this statement in some if statements checking that the monitors are configured as the line expects. You could end up with a system with no graphical display if one or more of the ports are not connected. I know, I've made this mistake.

Good to know, thank you. I'll play around a little it with that and update the guide up top.

[mattlach]

@mattlach Thanks mate !

The login orientation of my second monitor was driving me insane .

I'm glad it was helpful!

[EvilSupahFly]

I upgraded from LM20 to LM21 and lost my login display settings. I came upon your guide after questing on Google but it didn't work. My login screens are still the wrong resolution, but everything is fine once I log in.

[EvilSupahFly]

I found a better solution:

Instead, login and set your preferred screen settings (click "Apply" if anything changed), then open a terminal and run this command:

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sudo cp ~/.config/monitors.xml /var/lib/lightdm/.config/monitors.xml

Login resolution should now reflect the settings of the user signed in. Some people suggest making a hard link:

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sudo ln ~/.config/monitors.xml /var/lib/lightdm/.config/monitors.xml

But that only works if your home folder is on the same physical drive. Since my OS is on a different physical drive from my user folder (~), I had to copy the file instead of linking it. Note as well that it must be a hard link - symbolic links will not work.

[SMG]

I found a better solution:

What desktop environment of Linux Mint are you running and when did you last do a fresh install?

LM20 Cinnamon (and newer) versions do not have a monitors.xml file. They have a cinnamon-monitors.xml file.

[EvilSupahFly]

I found a better solution:

What desktop environment of Linux Mint are you running and when did you last do a fresh install?

LM20 Cinnamon (and newer) versions do not have a monitors.xml file. They have a cinnamon-monitors.xml file.

I'm running LM21 but I've been upgrading-in-place since LM16. Last clean install was LM16. Naming the file cinnamon-monitors.xml would probably work too.

[SMG]

Moderator note: WolvenSpectre's issue can now be found here Problems making Log in Screen use same Display Properties as When Logged in on LM21 because, as indicated right at the top, "Don't add support questions to tutorials please; start your own topic in the appropriate sub-forum instead."

[Berlyn]

I know this isn't the most valuable reply to the thread, but I made an account on these forums just so I could say that this tutorial was immensely helpful. I used it to get my portrait monitor to appear correctly instead of sideways. Thank you.

[PaulL]

I just want to say thank you for this tutorial. I only discovered the tutorials section of this forum by accident, and I'm glad I did. You solved the exact problems I've been looking for help for.

I had a moment of panic, because I entered the location of your script file instead of my own, and so on rebooting I got black screens with blinking cursors. But it only took a moment's thought to figure out what the problem was, and now I can log in with my cursor functioning properly and my background properly displayed. Again, thank you so much!

[JezekiljMonk]

HI mattlach
Thanks for posting this tutorial.
I tested it first of all on my linuxmint machines in VirtualBox. It turns out that it works on Linuxmint 20.x and 21.x for Cinnamon and only on Linuxmint 21.x with MATE, but not with Linuxmint 20.x with MATE. Don't know yet if this could be something related to VirtualBox but still I am only testing with MATE, not exactly working so it didn't even matter.
In order to test faster I wrote a short script that basically does everything you wrote, except for adopting AndyMH proposal and create file 91-slick-greeter.conf instead of 90-slick-greeter.conf.

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#!/usr/bin/bash
a=$(xrandr --verbose | awk -F'[ +x]' '$2=="connected" { if ($3=="primary") {print " --output "$1" --primary --mode "$4"x"$5" --pos "$6"x"$7" --rotate "$10} else {print " --output "$1" --mode "$3"x"$4" --pos "$5"x"$6" --rotate "$9}}; $2=="disconnected"{print " --output "$1" --off"}')
echo "Enter file name to save current configuration!"
echo "Please, no special character at the end of the file name"
name_of_file=''
while [[ -z $name_of_file ]]
do
    read -p "Please, only letters, numbers, dot '.', hyphen '-' and underscore '_': " name_of_file
    if [[ ! -z "$(echo $name_of_file | sed 's/[a-zA-Z0-9._-]//g')""$(echo ${name_of_file: -1} | sed 's/[a-zA-Z0-9]//')" ]]      # When name is correct both these strings will be empty so also the resulting string is empty
    then
        name_of_file=''     # When file name is not OK there will be new input request
    fi
done
name_of_file+=".sh"
echo "#!/bin/sh" > ~/.config/$name_of_file
echo "xrandr "$a >> ~/.config/$name_of_file
sudo mv ~/.config/$name_of_file /etc/lightdm/
sudo chown root:root /etc/lightdm/$name_of_file
sudo chmod 775 /etc/lightdm/$name_of_file
sudo bash -c "sed '1a "greeter-setup-script=/etc/lightdm/"${name_of_file}' /usr/share/lightdm/lightdm.conf.d/90-slick-greeter.conf > /usr/share/lightdm/lightdm.conf.d/91-slick-greeter.conf"
echo "That's it!"
read -p "Press Enter to exit"

[vimes666]

In case it still does not work:
I got an error in the syslog saying the desired mode was not found when the script was executed. I think that is a bug that occurs sometimes if the mode you are setting is the same as the current mode. In my case I only wanted to change the frequency for that mode.
I was able to fix this by adding a bare xrandr command right before the mode changing xrandr.

[egraeler]

FYI... I just upgraded to LM21.3 and this still works on that version as well. Thanks again for the nice write up!