Troubleshooting: Display Configurations Change with Downgrade of IGEL OS 11

You see an unwanted change in the display configurations when you are using multiple external displays and you downgrade your IGEL OS to 11.10.100 or later. After the upgrade, the configuration goes back to the original display config.

Environment

• Downgrading from IGEL OS 11.10.110 or later to IGEL OS 11.10.100 or later
• Hardware: Multiple external displays

Problem

With the 6.6.x kernel there was a bigger change in the connector enumeration handling of the i915 driver which causes the display connectors to switch after the downgrade. There is a default setting implemented that reverses the order back to the original, but for some hardware a manual reset is needed. 

Solution

Use the registry key to change the connector order of intel GPUs. As newer kernels changed the order this can be used to revert it to the former state:

1. In the IGEL Setup, go to System > Registry > x.drivers.intel.reverse_connector_enumeration.
   
   
2. Set the Reverse the connector enumeration parameter to Yes.