An engaging, accomplished cast and an insistently light tone recommend “Ezra,” another road trip bonding tale about autism and loved ones struggling to understand it.

The audience is always in on the “teachable moments” in movies from “Rain Man” and “The Last Right” to “Ezra.” We learn about autisim just as parents and strangers do in the movie.

The autistic character in such films invariably is a “Hollywood” version of “on the spectrum” — funny in just the right doses, contrived to be “manageable” when its convenient to the plot, with meltdowns just as predictable. But as loved ones and the medical community learn and pass on more about autism, screenwriters take that as license to lean hard on variations of “cute.”

Bobby Cannavale stars as Max, a former comedy writer who has aged into an edgy, confessional stand-up comic. His act has its funny bits, but it takes on other tones when he stops talking about his cranky ex-chef Dad (Robert DeNiro) and starts talking about “my son, Ezra.”

Ezra, played by William A. Fitzgerald, is a bespectacled autistic tween, growing up in Manhattan with his realtor Mom (Rose Byrne) and “making progress,” from “not talking” to “never shuts up.” He still can’t stand to be touched, still struggles with manic attention to movies and TV he’s exposed to — mostly when he’s visiting his Dad.

Quoting “Breaking Bad” doesn’t go over well in middle school. But maybe all that funny profanity eases the bullying.

“Fire in the hole, bitch!”

Max is on the cusp of a “big break,” as his agent (Whoopi Goldberg) has talked a talent scout for Jimmy Kimmel’s show into checking out his act. Being a father of a child with uncertain health and special needs, she’s figured Kimmel will dig this. Being a devoted dad, Max isn’t sure he can work this “break” in.

And meeting with reps from Ezra’s latest Hoboken school shows mother Jenna’s negotiating skills, and Max’s volcanic temper. She won’t say it, but Ezra’s picked up on the idea that she thinks his condition is inherited from Max, and that Max takes after his old man, the short-tempered union doorman, Stan (DeNiro).

That agent may not know that. But she knows something’s self-destructive about Max.

“I really want you to fly. But you’ve GOT to stop blowing up the runway!”

Ezra gets yanked from school and earns further attention from The State. So Max lashes out by grabbing the kid and taking him on a road trip.

“I’m saving my son’s LIFE!”

And nothing Jenna or her new man (Max won’t sign the divorce papers) Bruce (played by director Tony Goldwyn) can do will stop the reckoning that will come when they or the authorities catch up to them.

Cannavale as a frustrated stand-up comic works, even if the material is more believably-acted and filmed than amusing. Byrne is wonderfully under control as a mother who perhaps understands her child better, even if his indulgent Dad — who takes him, in costume, to Lebowski Fest — is the boy’s truest bond.

And Old Man DeNiro suggests a tempestuous hardcase who has mellowed, just a little, in this grandfather figure.

Goldwyn peppers his supporting cast with great players who find fun things to do around the edges. Goldberg’s agent has a habit of taking towering, over-40 Max into her lap. Rainn Wilson plays an amusing ex-comic and old pal who runs a kids camp in Michigan. Jacqueline Nwabueze plays an adorable Sengalese nun working at the camp.

And Vera Farmiga brings her brand of warmth to an old flame.

“Ezra’s” perfectly agreeable, pretty much start to finish. But boy, do the contrived elements of this plot — the ongoing pursuit of “Kimmel,” the underage kid’s mouthy “stepping on the punchline” habit when he’s in the comedy clubs as Dad does his act — grate.

The struggle between “cute” and “cloying” is real, and tends to blunt the emotional impact of the story.

But Goldwyn’s light touch ensures that the picture is never less than watchable, even if “Ezra” does have its share of “give me a break” moments.

Rating: R, profanity, fisticuffs, sexual situations

Cast: Bobby Cannavale, Rose Byrne, William A. Fitzgerald, Tony Goldwyn, Whoopi Goldberg, Rainn Wilson, Vera Farmiga and Robert De Niro

Credits: Directed by Tony Goldwyn, scripted by Tony Spiridakis. A Bleecker Street release.

Running time: 1:41