docs(linux): add notes on controller devices

docs/source/troubleshooting/linux.rst

@@ -33,3 +33,9 @@ If screencasting fails with KMS, you may need to run the following to force unpr
 Gamescope compatibility
 -----------------------
 Some users have reported stuttering issues when streaming games running within Gamescope.
+
+Controller works on Steam but not in games
+------------------------------------------
+One trick might be to change Steam settings and check or uncheck the configuration to support Xbox/Playstation controllers and leave only support for Generic controllers.
+
+Also, if you have many controllers already directly connected to the host, it might help to disable them so that the Sunshine provided controller (connected to the guest) is the "first" one. This can be accomplished on USB devices by finding the device in `/sys/bus/usb/devices/` and writing `0` to the `authorized` file.