Thank you for your help. I am trying to configure a Hyperkin X91 XBox controller to work with my Gallium OS system. Yes, Gallium is not Ubuntu, but it's based on the same stuff (I think?) so I thought an Ubuntu solution would work here.
In case you are not familiar with the X91 controller, it's an officially-licensed XBox controller, meaning I thought it would be plug-and-play like the XBox 360 USB controller. It is plug-and-play with Windows and Windows Steam, but not Linux Steam. My bad. Product info is here:
I am using Ubuntu 16.04, kernel 4.8.17-galliumos. I run apt-get update and upgrade all the time, so I think I am up-to-date.
I found this post by a guy in RetroPie's github who knows more than me: https://github.com/RetroPie/RetroPie-Setup/issues/1906 It looks helpful but I don't know enough to know how to use this info.
Is there any way I can some how edit something myself to tell my system, "Just treat it like an XBox 360 Controller"?
I am still trying to track down a driver and am trying to contact Hyperkin support.
All help appreciated. Thank you very much.