We broke the story ... the ex-NBA star was being investigated for allegedly getting violent with a man outside of a West Hollywood nightclub back in April.

Sources told us ... 32-year-old Davis was accused of almost hitting a man with his car and, when the man confronted Davis, he allegedly picked him up and slammed him on the concrete.

We're told the alleged victim was hospitalized for severe injuries including facial fractures, a broken tooth and broken ribs.

Law enforcement tells TMZ Sports ... Davis surrendered on Friday with his attorney and a bail bondsman. He was booked and released on $50k bail.