Wrong Login Screen Resolution

On the odd occasion, usually after incorrectly restarting my computer, my login screen resolution is not the default 1440x900, but I think 1600x900. Now, I have this monitor that's really bad at handling resolutions it's not designed to handle, and will show a silly "wrong resolution" box jumping around the screen.

Is there any way to make the login screen load a 1440x900 resolution no matter what? I'm running Ubuntu 11.10 with Unity and LightDM.

Solution 1:

You can make a script for this (source LightDM Resolution).

Firstly we need to find out what your monitors identifier is. Open up a terminal, start typing terminal in your unity dash to see the option or press Ctrl+Alt+T
Type/copy this command to show your display details:
```
xrandr -q
```
If you only have one monitor you will see a line in the output like the following (probably with some different values, its the identifier at the start we are after):
```
DVI-0 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 473mm x 296mm
```
The screen identifier is DVI-0 in this case
Open up your favourite text editor, lets use gedit for this example, press Alt+F2 and type gedit
Type/copy this in:
```
#!/bin/sh
xrandr --output DVI-0 --primary --mode 1440x900
```
Save this on your desktop as lightdmxrandr.sh
You may want to test the script before we put it into practice. Back in the terminal navigate to where we just saved it:
```
cd ~/Desktop
```
Now we need to make it executable:
```
chmod a+rx lightdmxrandr.sh
```
Now run it:
```
./lightdmxrandr.sh
```
(If your screen automatically auto-corrects after log in you probably won't see a difference so you may want to use a test resolution that is different but you know works while testing)
Now lets move the little script we made:
```
sudo mv ~/Desktop/lightdmxrandr.sh /usr/share/.
```
If you don't use sudo you may get a permission error (I use this folder out of personal preference)
We need to now run this in lightdm, navigate to the correct folder:
```
cd /etc/lightdm
```
Open up the lightdm conf file:
```
sudo gedit lightdm.conf
```
Now add the the instruction to run your script after the last line and save:
```
display-setup-script=/usr/share/lightdmxrandr.sh
```

Now reboot and that should set the correct resolution on your lightdm log in screen.

(these instructions might look long but they don't take long at all)

Solution 2:

I found a very simple workaround that works perfectly for me running 13.04. (update: now 13.10) on a laptop with a 24" external screen that is not permanently connected.

I'll just copy from here

log in

use xrandr or the Displays control utility to configure your monitors how you'd like them to be configured in the login screen

copy ~/.config/monitors.xml to /var/lib/lightdm/.config

Since I already had my monitors configured properly I just had to do step 3.

Some other answers given here worked for me but only in a specific scenario while running risk of an unusable system in other scenarios (LOW GRAPHICS MODE ERROR). For example with the external monitor permanently connected (accepted answer by @captain_G) or with always the same device connected to the output used for the external monitor (script by @Axlrod). It seems that @MarcoV's answer is the most generic solution, however it does still involve scripting rules.

Solution 3:

You can instead of creating script, just add to file /etc/lightdm/lightdm.conf a line like this:

display-setup-script=xrandr --output default --mode 1280x720

Before inserting make sure that command works, because with wrong command, lightdm will not start.

Solution 4:

sudo gedit /usr/share/X11/xorg.conf.d/52-myres.conf

then in the file:

Section "Monitor"
    Identifier "VGA1"
    Option "PreferredMode" "1152x864"
EndSection

Save and exit. The values were obtained from command xrandr -q. VGA1 is the name of my connector and 1152x864 is the name of the resolution.

This works for Xubuntu 16.04. It sets a preferred resolution and for me it let me set the resolution of the login screen, instead of having it default to the highest resolution supported.

Modified from answers here

Solution 5:

For a multi monitor setup where you might disconnect your laptop and use without, here is a simple solution:

run:

xrandr

Get the devices you are using laptop is usually LVDS1, and for me I have a DP2 (displayport 2) it could be HDMI1 or anything else, just find the ones with resolutions listed next to them.

Create this small bash file:

#!/bin/bash

mode="$(xrandr -q|grep -A1 "DP2 connected"| tail -1 |awk '{ print $1 }')"
if [ -n "$mode" ]; then
  xrandr --output LVDS1 --off
  xrandr --output DP2 --primary --mode 2540x1440
fi

Replace LVDS1 with your laptop monitor connection.

Replace DP2 with your external monitor connection.

Place bash script in /usr/bin/local/

chmod +x the script

edit /etc/lightdm/lightdm.conf

Add

display-setup-script=/path/to/my/script

Reboot.

The resolution change will only happen when you are actually at that display now.

If you have multiple places with different monitors / resolutions on same connector you will have to put more intelligence in your bash script.