Problem Description:
I am using the newer laptop with laptop screen resolution of 2560x1600 on one site with a monitor with 2560 x 1440 and on the other site with a monitor with 1920x1080.
The problem with the login screen is very unpleasant with the 1920x1080 monitor because the lightdm login screen is not shown fully and does not seem to adjust automatically to the resolution. The elements in the top bar are missing on the right upper side
I searched on the net and there were only some suggestions for bash scripts to adapt this with /etc/lightdm/lightdm.conf .
Is there some user defined way to change this without scripts?
I would probably give us more context if you could share the report from
inxi -CMNSGxxx
Are you saying that your laptop has 2 OS instances,
one booting with grub definitions for 2560 x 1440, and
the other with grub definitions for 1920x1080?
If not, how are you
connecting the monitors (type of interface)?
specifying the use of the resolution choice at boot/login?
If you are looking to have a resolution choice at login, there is no standardized Panel App available which offers that on the LightDM Panel.
Out of curiosity, I queried Google with the following:
linux lightdm is there a way for the system to open a pop-up, before opening lightdm, to prompt the user for a selection of display resolution from a menu of options
No, this is one Ubuntu 24.04 on one laptop used on two different sites with 2 different monitor and the display of the laptop.
It is ok on the display of the laptop (2560x1600) of course, does not make much difference on the 2560 x 1440 monitor but is very wrong on the 1920x1080 monitor.
All regarding the login screen/greeter screen.
Grub is not affected since I use the character grub which is installed initially.
I had the hope that this is done automatically depending on the resolution for the HDMI connection, but this seems to be ongoing work according to some articles.
The laptop screen is used for login additionally, when one of the monitors is conncted via HDMI.
Monitor 1 and Monitor2 are not used at the same time.
Monitor 1 is capable of 300Hz refresh,
Monitor 2 is capable of 140Hz and I want to use the max as far as possible.
The Hz are not the problem currently, but the monitor 2 with 1920x1080 shows only parts of the login screen. I guess that Ubuntu cannot switch the login/greeter screen automatically to 1920x1080 for HDMI and uses the 2560x1600 from the laptop which makes this kind of distorted login/greeter screen. I think it is mainly a problem between laptop and monitor 2.
And this is afaics a problem of the login/greeter screen which cannot adapt to a monitor connected to HDMI if at the same time the login screen/greeter screen is shown on the laptop.
That almost sounds like you want to emulate a docking station “re-calibration” to external display whent that connection is made pre-boot.
That is definitely beyond my experience base!
But my gut feeling is still pointing at either a systemd-based “trigger/action” or, maybe upstream as part of the boot via customized
GRUB_CMDLINE_LINUX_DEFAULT
which would override the GRUB assignment for
GRUB_GFXMODE
or have that only take effect if actions directed by “GRUB_CMDLINE_LINUX_DEFAULT” don’t detect the attached monitor.
As a strategy, maybe set up the external monitor as the default but with logic to fail-over to the internal if the external one is not detected. After all, if you have an image that is displayed smaller than the built-in monitor, at least you can access the entire area that is displayed.
