Ubuntu 16.04: X Server starts in low graphics mode when a device is connected
Symptom
Some users may experience X Server crashes when DisplayLink device is connected before login session starts, resulting in system going to low-graphics mode. This applies mainly to systems with NVIDIA GPUs. However, Intel GPU only machines could also be affected.
Solution
Configure evdi driver to add two DisplayLink devices on early boot stage. Unplug DisplayLink device. Select ‘Try running with default graphical mode’ to exit low graphics mode by clicking OK. If that does not help, then restart the machine.
Reboot and open terminal. Enter following commands:
Reboot and open terminal. Enter following commands:
echo "evdi" | sudo tee -a /etc/modules-load.d/modules.confecho "options evdi initial_device_count=2" | sudo tee -a /etc/modprobe.d/dkms.confA reboot is required for the setting to be effective.
Technical details
Xserver modesetting driver suffers from various GPU hot plug issues. Its crash during login phase causes XServer to run in log graphics mode. To mitigate that issue it is necessary to create evdi GPU devices before graphical session starts.