Patrick Mahomes Sr. Begins Jail Sentence For DWI Conviction

patrick mahomes sr mug shot TMZSports.com

Patrick Mahomes Sr. is back behind bars, but he has not been accused of further wrongdoing -- TMZ Sports has learned he's simply begun serving his sentence for his most recent DWI conviction.

A Smith County jail official tells us ... the father of NFL superstar Patrick Mahomes was booked on Tuesday afternoon at around 4:53 PM and took a new mug shot. He's now not expected to be released until Halloween.

patrick mahomes dad and patrick mahomes getty 1 Getty

Of course, the 10-day stint in the slammer was all planned ... as it was a condition of the plea agreement Mahomes Sr. reached with prosecutors stemming from his Feb. 3 arrest for drunk driving in…