How to force Multiple Monitors correct resolutions for LightDM?
- by Hanynowsky
I am affected by the BUG: https://bugs.launchpad.net/ubuntu/+source/unity-greeter/+bug/874241
Otherwise, if like me you have a laptop connected to a second monitor of higher resolution, LIGHTDM at the login stage, mirrors the displays in both screens and assign to them a common resolution (1024X768) in my case, instead of extending the desktop (Primary screen with the greeter and secondary with just a logo as mentioned in the Multiple Monitors UX specifications book for 12.04).
Here is my xrandr -q
@L502X:~$ xrandr -q
Screen 0: minimum 320 x 200, current 1920 x 1848, maximum 8192 x 8192
LVDS1 connected 1366x768+309+1080 (normal left inverted right x axis y axis) 344mm x 193mm
1366x768 60.0*+
1360x768 59.8 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 287mm
1920x1080 60.0*+
1600x1200 60.0
1680x1050 60.0
1280x1024 60.0
1440x900 59.9
1280x960 60.0
1280x800 59.8
1024x768 60.0
800x600 60.3 56.2
640x480 60.0
DP1 disconnected (normal left inverted right x axis y axis)
I tried to force lightdm to execute some xrandr commands in order to set the right resolution for each monitor and extend the desktop, but I get a LOW GRAPHICS MODE ERROR (You're running in low graphics mode, your screen, input devices...did not get detected..)
I created a simple script named lightdmxrand.sh:
#!/bin/sh
xrandr --output HDMI1 --primary --mode 1920x1080 --output LVDS1 --mode 1366x768 --below HDMI1
And told lightdm to run it : /etc/lightdm/lightdm.conf
[SeatDefaults]
greeter-session=unity-greeter
user-session=ubuntu
greeter-setup-script=/usr/bin/numlockx on
display-setup-script=/home/hanynowsky/lightdmxrandr.sh
Someone knows what is wrong!?
Thanks in advance.
