RE: Dell XPS15 9550 Ubuntu 16.04
I did disable it. But I'm not sure I had to.
My first attempt failed. Because I was at Ubuntu 15.10 (no windows)
I wiped the drive, installed WIndows 10, updated the firmware/bios, then set bios to factory default.
That's when things got weird.
So I removed RAID support and re-enabled UEDI access from the OS.
Re-installed Windows 10 and all it's drivers. Then Installed Ubuntu, enabled proprietary drives, installed kernel 4.5.2. All is working great!
My only complaint is the trackpad. I had it perfect before. I can't remember what I did...