How to play Left 4 Dead 2 in split screen with two controllers?

I would like to know if anybody managed to play L4D2 in split screen under Ubuntu/Linux with 2 controllers and how it was achieved.

I tried using different guides like this one; split screen works, first player is controlled by controller 1 but nothing ever controls player 2.

I successfully used the xboxdrv driver to manage 8 wireless Xbox 360 controllers (with some scripts). Controllers work fine on games like Knight Squad, ClusterPuck 99, Portal 2 (Source game + 2 controllers), Screen Cheat, etc.

I successfully launch Left 4 Dead 2 in split screen with this addon. But nothing controls the second player.

I tried the different proposed solutions concerning the modification of the 360controller.cfg file, but nothing changed.

I use Ubuntu 14.04.

Know someone who can answer? Share a link to this question via email, Twitter, or Facebook.