On Windows it works in Unity. Gamepad works fine in Linux, I tested it. But with Unity (on Linux) it doesn’t.
Can you provide more information?
What gamepad is it?
Does it not work with the Unity player, or editor, or both?
Did it work with Unity 5.5?
Gamepad: Mad Catz CTRL R.
I tested it in Game view.
In Unity 5.5 and 2017 it doesn’t work too.
I’ve had the same issue in 5.6 Linux builds as well as the Linux Unity editor since to 5.6. Prior to 5.6, my controller boards worked. JSTest picks up the inputs just fine, but they don’t work with Unity 5.6 Linux builds or editor. I’ve tried this with Xin-Mo Dual Player boards and Ultimarc MiniPAC boards. Haven’t made the switch to 2017 yet, so I’m not sure there.