Originally Posted by danix
I'm noticing that a lot of the laptops mentioned in this thread have multiple GPUs (integrated GPU + discrete). I'm not sure to what level these sorts of things are supported... Try going into your BIOS to disable any "Hybrid GPU" features, and the integrated GPU, if possible, and see if that helps at all.
It's not the hybrid GPU option. I have a Sony VAIO CW that does not advertise hybrid GPU functionality, nor is there any information of hacking to an enabled state online.
There was another thread that discovered the EDID is loaded by ACPI _anyway_, and the main laptop screen can be enabled with this:
Option "CustomEDID" "DFP-0: /proc/acpi/video/NGFX/LCD/EDID"
Everything related to monitor detection is really messed up on these cards right now.