4 April 2017

The solution for me was to use Noveau drivers instead of Nvidia proprietary drivers. I have a LG 25UM57-P monitor that has 2560x1080 21:9 resolution. It worked perfectly on Dell Latitude, but on Dell Precision the option was just gone. I have tried multiple solutions, tried to disable edid file limitations, but nothing worked.

I had Nvidia proprietary drivers installed and wished to keep those. Since I use Arch Linux so the nouveau package for me is "xf86-video-nouveau". 
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  1. sudo pacman -S xf86-video-nouveau
Programming Language: Bash
Then I had to disable nouveau blacklisting. In "/usr/lib/modprobe.d/nvidia.conf" or if you use legacy nvidia for older cards then the configuration file name may differ. It's highly recommended to uninstall the nvidia package or after upgrade there might be some anomalies, since this was reset after nvidia package got updated.
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  1. #blacklist nouveau
Programming Language: Text
Add nouveau to xorg configuration. In "/etc/X11/xorg.conf.d/20-nouveau.conf".
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  1. Section "Device"
  2.     Identifier "Nvidia card"
  3.     Driver "nouveau"
  4. EndSection
Programming Language: Text
Re-generate the initial ramdisk image, using your kernel preset(linux in my case):
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  1. sudo mkinitcpio -p linux
Programming Language: Bash