I recently tried playing War Thunder on Linux but the game was not detecting my Thrustmaster T-Flight H.O.T.A.S X. I had a similar issue on Windows 10, the fix is the same for both as it is an issue within Steams settings.
Steam Controller Settings
To get to the Steam controller settings first go to the top left Where it says Steam and click on settings. You then click on Controller to highlight controller from there you go click on The top option which is general controller settings. Once inside make sure to check the box for generic game-pad configuration support.
This will allow you to configure controller support on a per game basis. What you need to do next is go to the game that is not detecting your controller in my case War Thunder and change the steam input per game setting to force on.
To do this you go to your steam library and right click the game in question and click on properties.
Mid way down the general tab you will find the Steam Input Per-Game Setting. Change this setting to Force On and bingo bango the next time you load your game, your controller should be recognized.
Once you have loaded the game and it has detected your controller log back out of the game and return the settings to how they were. Go back in and uncheck generic game-pad controller support in steam and then return the per-game setting in the effected game to use global settings. Load the effected game up once more and it should again detect your controller. If you do not do this last step games that already detect your controller may no longer detect your controller.
This fix works on any Steam game that is not detecting your controller. Most Steam games already work great out of the box thanks to Valves efforts to get all games on Steam working with controllers.
Having issues getting a game to detect your controller? Leave a comment below or better yet head to our forums and we will do our best to help get you up and going.