Chris Brown took his daughter Royalty for a slow spin on his ATV ... as part of an early celebration for her 2nd birthday.

It looks potentially perilous -- he's hangin' on to Royalty and Tyga's kid King Cairo -- but Chris was going super slow and the kids loved it.

It was a far different scene a few days back, when neighbors called the cops on Chris for doing doughnuts on the street and a few lawns. The cops came and the L.A. City Attorney is currently reviewing the case of possible disturbing the peace prosecution.