Coolio: The Whole Gun Arrest Thing ... "A Little Misunderstanding"

Coolio passed off his arrest for trying to take a loaded firearm onto a plane as "a little misunderstanding."

Coolio posted a video of him chowing down on orange chicken at P.F. Changs after he was released from jail.

TMZ broke the story ... TSA flagged the gun in a book bag and a member of his crew took the fall, saying it was his. Coolio boarded the plane but cops got wise, yanked him off and arrested him for possession of a firearm by a felon.

The rapper was undeterred, vowing to make it to Indio, near Palm Springs, for Sunday's "I Love the 90s" concert.

He should have driven.