Retroarch doesn't recognize /dev/uinput events?

Hi,

I have a controller that sends key events using /dev/uinput, and it does not work with retroarch on my RPi3.

For comparison, I can run the stand alone version of gambatte like so, and use my /dev/uinput controller mapped accordingly. gambatte_sdl -i j g x z up down left right -s 3

But the retroarch version of gambatte is unresponsive to my /dev/uinput controller when run as below, even though it responds to the keyboard using the same keys as above. /opt/retropie/emulators/retroarch/bin/retroarch -L /opt/retropie/libretrocores/lr-gambatte/gambatte_libretro.so --config /opt/retropie/configs/gb/retroarch.cfg

Any ideas or tips?