https://bugs.freedesktop.org/show_bug.cgi?id=93548
--- Comment #3 from Edwin Smith esmith@feralinteractive.com --- I am pretty sure this is the bug with xpad that can cause hangs when using force feedback. This was reported by Feral during development of XCOM and was fixed for SteamOS by Pierre-Loup but the fix has not made it's way upstream to the main linux kernel.
This was fixed by Sarah Bessmer (see link here)
http://www.spinics.net/lists/linux-input/msg31450.html
Pierre-Loup also fixed the issue separately himself for the SteamOS drivers.
Sarah's fix has been used by a number of people with a lot of success and we have also confirmed the SteamOS drivers don't see this issue so hopefully one of the two fixes can be merged into xpad to fix this problem.
Hope this background helps!