Unable to set supported resolution manually
I am trying to get my external monitor (LG 27UL550-W) to work on 4k@60Hz with my Laptop (Lenovo ThinkPad E480 running Linux) using a USB-C dock via an HDMI Cable.
4k@60Hz works when using the same hardware (Cable, Monitor & Dock) with my friends MacBook Air M1.
I tried setting the resolution manually, as described here: https://wiki.archlinux.org/title/Xrandr#Adding_undetected_resolutions, which resulted in the following commands:
xrandr --newmode "3480x2160_60.00" 645.25 3480 3768 4144 4808 2160 2163 2173 2237 -hsync +vsync
xrandr --verbose --addmode DP-1 "3480x2160_60.00"
xrandr --verbose --output DP-1 --mode "3480x2160_60.00"
This gave the error:
crtc 2: 3480x2160_60.00 59.99 +0+0 "DP-1"
xrandr: Configure crtc 2 failed
crtc 0: disable
crtc 1: disable
crtc 2: disable
crtc 3: disable
crtc 4: disable
crtc 5: disable
crtc 6: disable
crtc 7: disable
screen 0: revert
crtc 0: revert
crtc 1: revert
crtc 2: revert
crtc 3: revert
crtc 4: revert
crtc 5: revert
crtc 6: revert
crtc 7: revert
As the laptop is, according to the manual, supposed to support 4k@60Hz via USB-C and the hardware does support it (as tested) I really don't know what else could be the issue. Thankful for any idea.