Will only use the smaller size of a Multimonitor system with different screen sizes about slick-greeter

[clefebvre]

Is this specific to slick greeter or lightdm? Can you reproduce the issue with lightdm-gtk-greeter for instance?

[nd4c]

lightdm-gtk-greeter does the reverse. It uses the largest resolution for both screens, so that the smaller screen is now messed up.

There is also a difference in how they hand off the displays after logging in. slick greeter will have the screen go blank for a sort of long time and then the desktop displays. gtk greeter, on the other hand, does not blank out the screen, and you see a messed up desktop and it trying to change the resolutions to match both windows. Finally it settles down and the desk top looks normal.

[nd4c]

Another note about the lightdm greeters. Both are apparently just duplicating the screen on both monitors. As I type in the password, either greeter will show me typing it in on both monitors.

[nd4c]

lightdm-gtk-greeter has had this problem since 2014. In 2017 Ubuntu confirmed the bug:
https://bugs.launchpad.net/lightdm-gtk-greeter/+bug/1314603

[clefebvre]

Both are apparently just duplicating the screen on both monitors.

That's weird... it should show the background on both monitors, but the password box and user list should only be visible on the monitor where your mouse cursor is.

You've got a mouse cursor on each monitor?

Maybe you're mirrored at Xorg.conf level?

[clefebvre]

Check /var/log/lightdm/seat0-greeter.log.

Here's mine with dual monitors... everything works fine here:

[+0.23s] DEBUG: main-window.vala:205: Screen is 4480x1440 pixels
[+0.23s] DEBUG: main-window.vala:213: Monitor 0 is 1920x1200 pixels at 0,0
[+0.23s] DEBUG: main-window.vala:213: Monitor 1 is 2560x1440 pixels at 1920,0
[+0.23s] DEBUG: slick-greeter.vala:677: Showing greeter
[+0.23s] DEBUG: slick-greeter.vala:291: Showing main window

And

[+0.25s] DEBUG: background.vala:68: Making background /usr/share/backgrounds/linuxmint-sonya/jenemark_conifer_cone.jpg at 1920x1200,2560x1440
[+0.38s] DEBUG: background.vala:121: Render of background /usr/share/backgrounds/linuxmint-sonya/jenemark_conifer_cone.jpg complete

[nd4c]

@clefebvre

In answer to the mouse cursor question. Yes, the mouse cursor is on both monitors - exact duplicate screens. You mentioned being mirrored at the Xorg.level. Not sure how to change that, especially for just the login screen. Once I'm logged in the monitors work fine as expected.

For the post about the log, the computer in question is my home desktop and I'm not at home. Will check when I can.

[clefebvre]

Ok, if your mouse cursor is on both screens, you're definitely mirrored.

The display settings you manipulate in your sessions, only apply to your DE. The DM itself follows your Xorg configuration.