Griffin pleaded guilty to two felony counts of driving under the influence of drugs and gun possession charges, both of which stemmed from a car crash in August.
The eldest son of the Peyton Palace actor, who first entered his plea in November, was facing a maximum of four years behind bars after veering towards oncoming traffic and injuring the driver of a van in the collision.
Griffin missed his initial sentencing hearing last month as he was seeking rehab treatment for alcohol issues, E! reports.
His accident occurred hours after half-brother Redmond, whose mother is the late actress Farrah Fawcett, was arrested on a drug charge in Los Angeles.
In September, Redmond was jailed for using drugs in court-ordered rehab.