Question: I have a DisplayLink-based external USB monitor, which has both power and data over USB, and seems to work perfectly under Windows 7, but only can display a text console under Ubuntu 10.10, and that I can only use when I am actually switched to it. So the only Use I can have so far is to have some text-based monitoring or console that I can watch while working on the graphic display. 

I know there are some development done for DisplayLink, but I never could get it to actually run properly. 

Yes, I tried the detailed setup described in other [posts](https://askubuntu.com/questions/3348/how-to-get-lilliput-usb-monitor-running-in-ubuntu), but they did not work, and instead crashed my X that I had to restore. 

Merci :-)

Answer: 
Here's an easy way to test if your DisplayLink device is operable at a low level, under Linux. If you plug in the device and get a green screen, you're ready for the next step.

First convert a bitmap to the size of your screen, then convert it to 16 bit RGB color. Then copy to the framebuffer for the device:

```
convert -resize '800x480!' input.jpg temp1.png
mkdfiff -f RGB16 temp1.png > temp2.png
dd if=temp2.png of=/dev/fb1

```

Note that your DisplayLink is probably at /dev/fb1, but you can check with `dmesg` :

```
[581145.816821] udlfb: DisplayLink Kensington M01063 - serial #202241900817
[581145.817000] udlfb: vendor descriptor length:22 data:22 5f 01 0020 05 00 01 03 00 04
[581145.817005] udlfb: DL chip limited to 2360000 pixel modes
[581145.909488] udlfb: DisplayLink USB device /dev/fb1 attached. 800x480 resolution.

```

Only version 1 DisplayLink chips are supported by Linux.
The DisplayLink 1 chips are limited to 16 bit RGB.
Getting the device to work properly under X windows is more challenging.
In addition to callmebob's installtion guide on 18.04 I had to do the following routine:
Workaround 1: Disable PageFlip for modesetting

It is preferred to keep using "modesetting" driver, but disabling page flipping is necessary. 
To do this, as a root user create a file 20-displaylink.conf under:

/usr/share/X11/xorg.conf.d/

with the following content: 

```
Section "Device"
  Identifier "DisplayLink"
  Driver "modesetting"
  Option "PageFlip" "false"
EndSection  

```

A reboot is required for the setting to be effective.