Comment 19 for bug 812594

@Damion
All my tests were performed on Dell Vostro laptop with dual graphics (nVidia Geforce + Intel) and 2 displaylink devices. My aim is to get 4 screens: main (built in) + 1 on VGA output + 2 via displaylink.
Under Win XP stuff works perfectly, screen layout in whatever configuration and depth of colors up to 32 bit. Therefore I believe there are no limitations coming from hardware. I want to reproduce quality and layout in Linux. As far as I know my laptop will not use VGA nor HDI output if using Intel graphics only, so I'd rather keep nVidia working.

In openSuse I was using nouveau drivers for nvidia (open source), but also unable to get it working both with displaylink devices via framebuffer, but VGA output was also addressed via framebuffer, and displaylink screens stay green. From this I would conclude that kernel drivers are OK, system hardware parameters polling and reporting goes properly (checked via dmesg, udevadm, etc.) and only Xorg is unable to use this information.

Might be intresting, that Ubuntu 12.04.1 with Unity displayed xlogin screen onto dispalylink without any prior xorg.conf modification. Unfortunately it happened only once, probably by accident and later I couldn't reproduce this effect, except manual edit of xorg.conf, however I switched from Unity to KDE in the meantime.

Next tests: Linux Mint 13 and Ubutu 12.10 beta.