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 3840×2160 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.
Best Answer
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.