Comment 21 for bug 1853357

I tested with a Dell D3100 dock and two monitors connected to the dock via HDMI in addition to laptop built-in screen. I did this on Ubuntu 19.10 with the libmutter fix from eoan-proposed (libmutter-5-0 package version 3.34.3-1ubuntu1~19.10.1).

I tried unplugging and hotplugging each HDMI cable individually and together. I tried hotplugging and unplugging the dock itself (USB). I tried booting with the dock connected, and booting with the dock disconnected then hotplugged.

With all three monitors on, I left one glxgears running on one DisplayLink output and the laptop screen each, and a terminal printing the fps on the other DL output for 10 minutes. Then I changed the refresh rate of one DL output to 50 Hz and the other DL output to 75 Hz, confirmed from the monitors themselves to actually run with those refresh rates, and left things running for a couple of minutes more. (Everything defaulted to 60 Hz before.)

I was unable to reproduce any kind of freeze.

However, I did notice that with three monitors, gnome-control-center Display settings is crash-happy if any monitor was disabled. But that is off-topic here, because even that did not cause anything to freeze.

I did also observe the "outdated content" issue I referred to in my earlier comment here. That should be fixed in EVDI kernel module once DisplayLink releases an update.