USB port temporarily stopped working
All of a sudden, I noticed that the right-side USB port had quit working. I could get power from the port, but no data would transfer. When plugging a flash drive into the port, its indicator light would flash briefly but then go out. It didn't matter whether or not I inserted it quickly or slowly. Nothing would work on it, but the left-side port continued to work as usual. Even stranger, a restart fixed the problem, so it was apparently some software thing. Anyone able to shed a little light on what's going on?
MacBook Air (13-inch, Early 2014), OS X El Capitan (10.11.1)