I managed to get a USB 3.0 monitor AOCI1659FWUX working on my Pi 4.
I based it on this post, but with some updates: https://support.displaylink.com/knowled ... spberry-pi
DisplayLink driver version 4.4 can be used on Raspbian. The tests have been done using kernel 4.14.62-v7, Raspbian GNU/Linux 9 (Debian Stretch).
In order to run it do the following steps:
- Run $ sudo raspi-config
Then choose Advanced Options, GL Driver, and finally Full KMS (recommended) or Fake KMS.
Reboot in order to make the change effective.
Install dkms and kernel header files, e.g. via apt: $ sudo apt install dkms raspberrypi-kernel-headers
Install DisplayLink binaries via .run file. DO NOT connect the device yet.
After booting, connect the device. The screen won't be added automatically, so call $ xrandr --setprovideroutputsource 1 0 (or equivalent, if using other tools) Refer to $ xrandr --listproviders and $ xrandr --help to get the list of the appropriate parameters.
Enable the screen e.g. via xrandr: $ xrandr --output DVI-I-1-1 --on --auto The monitor connected to DisplayLink screen should display the first frame, then freeze.
Restart display manager, e.g. by calling $ sudo service lightdm restart
The desktop should appear on the monitor connected to the docking station, internal monitor should be disabled.
- Booting with DisplayLink device connected results in a crash.
After enabling DisplayLink screen, switching back to internal video output requires a reboot. Both screens are visible in xrandr but trying to switch them results in an error.
Total resolution limit for all screens is 2048x2048.
In case resolution limit is reached, please use display settings, xrandr or similar tool to set resolution before enabling the screen.
Switching to a virtual console requires the monitor to be connected to internal display output, e.g. HDMI.
I was only able to install the most recent DisplayLink binary drivers (5.2, not 4.4) and only Fake KMS existed in raspi-config, but this worked.
After rebooting, the display flickered on and off quickly, which I found to be a power issue (apparently the Pi 4 doesn't supply enough even through USB 3.0). But using the attached Y-cable. Once I supplied the second part of the Y-cable to an external USB supply, the display remained blank until I used the xrandr commands (although I had to drop the --on flag from the second command, since this no longer exists).
The display came to life and I now have an 8W 1920x1080 USB powered monitor on my Pi 4!