Displays

Color management

.ICC and .ICM are the same files, some may contain additional setting informantion, some may not. You can get them from windows driver distributions, by digging inside of the install archives

https://wiki.archlinux.org/index.php/Mac#Color_Profile

displaycal looks cool but is gnome based - depends on argyllcms and colord
kde's competing system is oyranos and kolormanager http://www.oyranos.org/kolormanager/, https://userbase.kde.org/Color_Management

after configuring puts .config/autorunz-...descktop file to run
displaycal-apply-profiles
that currently fails because colormgr command does not find the displays, but displaycal uses it to locate the display for running dispwin
you can run dispwin manually:
dispwin -v -d 1 ColorProfiles/Dell_U2412M.icm
to list displays run with dispwin --help and look at the -d section
to verify that it's loaded run
dispwin -v -d 4 -V ColorProfiles/Dell_U2412M.icm

colord has a bunch of gnome deps
installed colord-kde

compiling colord
tar xvf colord-1.3.5.tar.xz

sudo apt install intltool libgusb-dev docbook-utils libpolkit-gobject-1-dev
sudo apt install liblcms2-dev libgudev-1.0-dev libsqlite3-dev libsystemd-dev libdbus-1-dev
1534 ./autogen.sh
1537 make
1539 sudo make install
1540 sudo systemctl restart colord.service
1541 sudo systemctl daemon-reload
1542 sudo systemctl restart colord.service

Edid

list avaiable -
sudo get-edid

grab
sudo get-edid -b 4 > 4.edid

view in Xorg.conf format

parse-edid < 4.edid

Print edid

#!/usr/bin/env python2

import sys
from DisplayCAL import edid

with open(sys.argv[1], 'rb') as edid_file:
    edid_blob = edid_file.read()
    edid_data = edid.parse_edid(edid_blob)
    for k, v in edid_data.iteritems():
        if k != 'edid':
            print k + ':', v

DisplayLink notes

Syslog has too many evdi messages
Reduce evdi logging (evdu is bundled with the displaylink driver). Switch it to warn - https://github.com/DisplayLink/evdi/blob/devel/module/evdi_debug.h

sudo bash -c "echo \"options evdi initial_loglevel=3\" > /etc/modprobe.d/evdi.conf"

How to change brigtness on a USB DisplayLink display
ddcutil did not work with displaylink. DDC/CI is supported on windows for the the DL-1x5 and DL-4xxx

Adjust gamma with xrandr did not work either
xrandr --output DVI-I-2-2 --gamma 2:2:2

Known Issues
DisplayLink supports up to two full HD monitors. It is possible to connect and use more but this is not tested or supported by DisplayLink.
Rotation is not supported due to missing functionality in the generic modesetting driver
Closed source AMD/NVIDIA drivers are incompatible with DisplayLink driver. Please use open-source AMD/NVIDIA drivers instead.

Get detailed info
Download the Linux support tool.
sudo ./DLSupportTool --debug

Get a name of the kernel display driver/module and make sure it's connected
modesetting as verified by
xrandr --listproviders
Providers: number : 3
Provider 0: id: 0x cap: 0x, Source Output, Sink Offload crtcs: 4 outputs: 6 associated providers: 2 name:Intel
Provider 1: id: 0x cap: 0x, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting
Provider 2: id: 0x cap: 0x, Sink Output crtcs: 1 outputs: 1 associated providers: 1 name:modesetting

In the above output, we can see that provider 0 is the system's regular graphics provider (Intel), and provider 1 (modesetting) is the DisplayLink provider. To use the DisplayLink device, connect provider 1 to provider 0:

$ xrandr --setprovideroutputsource 1 0