Ubuntu and changing resolution to 4K

Question

I did search and do a script:

$cat ./xrandr 
cvt 3840 2160 59.91
xrandr --newmode "4K" 711.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
xrandr --addmode XWAYLAND1 4K
xrandr --output XWAYLAND1 --mode 4K`

But now even that in the settings-->devices-->screen resolution I did not have a 3840x2160 mode to choose in the list.

When I run my script:

$ bash -x ./xrandr 
+ cvt 3840 2160 59.91
# 3840x2160 59.90 Hz (CVT) hsync: 133.99 kHz; pclk: 711.75 MHz
Modeline "3840x2160_59.91"  711.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
+ xrandr --newmode 4K 711.75 3840 4160 4576 5312 2160 2163 2168 2237 -hsync +vsync
X Error of failed request:  BadName (named color or font does not exist)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  16 (RRCreateMode)
  Serial number of failed request:  18
  Current serial number in output stream:  18
+ xrandr --addmode XWAYLAND1 4K
+ xrandr --output XWAYLAND1 --mode 4K
xrandr: Configure crtc 0 failed

What is the solution for that? I have Ubuntu 17.10. I had this resolution earlier...it just disappear.

Solution

All the problem was due to "Display Port 1.2" in Monitor Settings. Changing back to "Display Port 1.1" resolved problem. The resolution is in the list in gnome display settings.

It was really hard to diagnose that.

Comments

[dobey]

You cannot use xrandr to add resolutions under Wayland. What do you mean you had this resolution earlier? Where you logged in under Xorg instead? Were you on 17.04, and after upgrading to 17.10 you don't see the resolution under Wayland?

[Mario_bash]

I did full install of ubuntu 17.10. Connected 4K monitor and It was all OK to the moment I change down resolution to 2560x1440 mode.

[Mario_bash]

I tried to change to Xorg but there is no even 2560x1440 resolution in this list.

[dobey]

Do you want 2560x1440 or 3840x2160? Have you tried setting to 1920x1080 and then rebooting to see if you can get 3840x2160 working again?

[Mario_bash]

I would like to change to 3840x2160.

[Mario_bash]

Tried to change to FullHD and reboot. That doesn't resolve my problem.

[Mario_bash]

I boot from USB - got this display resolution :/

[dobey]

Do you get the same errors from xrandr if you try to add this mode under Xorg, and select it? If so, I'd suggest opening a bug with the details.

[Mario_bash]

I use wayland not X11.

[Jermayne Williams]

ok sorry about that. I haven't used wayland yet. I cant really give you much advice on that.

[shrw]

where ica n find this option in 18.04