[XORG] Kubuntu boots up with resolution out of range

[bradleypariah]

Roughly 75% of the time, when I turn my computer on, after passing BIOS and GRUB, the PC switches to a resolution that is out of range of my display. Same hardware I've been running on Kubuntu for a few years now with no such issue. Started directly after installing 23.10, which I admittedly upgraded to a few weeks ago.

I know Kubuntu is making it to SDDM, because even though my monitor says, "Out of range," if I blindly enter my password, I hear the login music (yes, I still play login music). After that, if I turn off my display, then turn it back on again, the PC and display apparently exchange EDID and I am greeted by my already-logged-in desktop.

If my display ever goes to sleep while I was logged in but inactive for a while, when I wake it up, my desktop is out of range again, and about 50% of the time for that, rebooting the display doesn't work, and I have to reboot the PC, which of course leads to the possibility of SDDM being out range again.

I am using X11. I have tried with Wayland, but it made no difference.

Everything else about my experience is fine, but this is starting to drive me a little crazy. I have Googled "SDDM out of range" and various other things, and I see some people suggesting to edit GRUB with my desired desktop resolution, but I tried that already, and it didn't work.

Below is my xrandr. Sorry for asking what's probably such a basic question, but how to I always force my DisplayPort-0 mode to 1920x1080_60.00?
Everything I'm finding online is either Ubuntu/Gnome-specific, or outdated, or I just can't figure out how to translate their advice to my scenario.

$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1920x1080 60.00*+ 120.00 119.88 50.00 59.94 30.00 24.00 29.97 23.98
4096x2160 30.00 25.00 24.00 29.97 23.98
3840x2160 30.00 25.00 24.00 29.97 23.98
2560x1600 59.97
2048x1536 60.02
1920x1440 60.00
1856x1392 60.00
1792x1344 60.00
2048x1152 60.00
1920x1200 74.93 59.95
1600x1200 75.00 70.00 65.00 60.00
1680x1050 84.94 74.89 59.88
1680x945 60.02
1400x1050 84.96 74.87 59.95
1600x900 60.00
1280x1024 85.02 75.02 60.02
1440x900 84.84 74.98 59.90
1280x960 85.00 60.00
1366x768 59.79
1360x768 119.97 60.02
1280x800 119.91 84.88 74.93 59.91
1152x864 75.00
1280x768 119.80 84.84 74.89 59.99
1280x720 60.00 50.00 59.94
1024x768 119.99 85.00 75.03 70.07 60.00
1024x576 59.97
832x624 74.55
800x600 119.97 85.06 72.19 75.00 60.32 56.25
720x576 50.00
848x480 60.00
720x480 60.00 59.94
640x480 119.99 85.01 75.00 72.81 66.67 60.00 59.94
720x400 85.04 70.08
640x400 85.08
640x350 85.08
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-2 disconnected (normal left inverted right x axis y axis)
HDMI-A-0 disconnected (normal left inverted right x axis y axis)

[claydoh]

Don't rule out hardware, namely cables, which is is an easy thing to eliminate as a cause.
Can't say *why* but you can try different things.
You can set a resolution in Grub, and see if that holds through until and including SDDM.

SDDM itself is running a simple xorg setup, until one logs in, in which the system or user xorg or wayland settings take over.
You can set a custom xrandr command in an SDDM config to do this, using the output you gave:

create or edit /usr/share/sddm/scripts/Xsetup and add:
xrandr --output DisplayPort-0 --mode 1920x1080

[bradleypariah]

Thank you. Already tried editing grub. Grub already shows fine, but the resolution seems to change right before the login screen appears.

I don't believe my cable is bad, because the issue propped up the literal minute I upgraded to 23.10, it has been working fine for years, and the monitor reliably shows an image from BIOS and GRUB before dropping out right before SDDM. The monitor even says in the little popup "1080p" before getting to SDDM, at which time it switches to "Searching," and eventually says, "Out of Range." So it's definitely something software side that triggers the issue at a specific point every time.

Once I'm logged into the desktop, and I have an image, it never drops out again (unless the PC or monitor go to sleep).

Does it matter where within that file I paste the xrander line? There's a lot of "if"s and "fi"s and open/close brackets around other code. Does this just sit off by itself at the beginning (or end)?

[claydoh]

I don't believe my cable is bad, because the issue propped up the literal minute I upgraded to 23.10,

it is just an easy thing to quickly and easily rule out. Over the years I have had many hardware problems that happened with a system upgrade or update that were actually physical issues (like bum cables), and not software.

Does it matter where within that file I paste the xrander line? There's a lot of "if"s and "fi"s and open/close brackets around other code. Does this just sit off by itself at the beginning (or end)?

You can post the contents if you are not sure. A separate line at the end is perfectly fine.

[kevin01523]

this actually happened when i upgraded from 22.04 to 23.04

[bradleypariah]

this actually happened when i upgraded from 22.04 to 23.04

How did you solve it?

[bradleypariah]

create or edit /usr/share/sddm/scripts/Xsetup and add:
xrandr --output DisplayPort-0 --mode 1920x1080

I'm hesitant to say the issue is fixed, because days have gone by previously where the problem didn't appear, and it came back, but I can say that since typing that line into that file, the issue has not resurfaced.

I've only turned the computer completely off and back on again a handful of times since then, but I am hopeful!

I appreciate your constant willingness to help everyone.

[claydoh]

I appreciate your constant willingness to help everyone.

I wish we were able to determine *why* it happened, in case there was a real fix, as opposed to a workaround.

[bradleypariah]

I wish we were able to determine *why* it happened, in case there was a real fix, as opposed to a workaround.

Unfortunately I have discovered that the workaround did not work. It's still doing the same thing.

Upon booting my PC, my display shows BIOS and then GRUB just fine, and my displays says "1080p" in a little white notification in the bottom right. If the bug hits, then the screen goes black right after GRUB, and never comes back.
I can tell the bug is going to happen, because the little white popup that said "1080p" a few second before comes back, and it says, "Searching." After 30 seconds or so, the notification says, "Out of range."
If I enter my password to the black screen, I hear the login music.
If I power cycle my display once or twice after that, the resolution catches, and the desktop shows, and my monitor verifies "1080p" in the little popup.
If I never enter my password, and I just sit and wait, it stays out of range, and the display eventually turns off. I don't get it.

Cable is definitely good.
Once the EDID handshake happens properly, the desktop is stable all day. Not to mention I never have any issues seeing BIOS or GRUB.
The issue only happens right after GRUB, and then only sometimes.
The display has no issues with any other sources, and the desktop never drops out at any other times. It only happens between GRUB and SDDM, if it happens.