Answer the question at the end by quoting:

Black Flag was an American punk rock band formed in 1976 in Hermosa Beach, California. Initially called Panic, the band was established by Greg Ginn, the guitarist, primary songwriter, and sole continuous member through multiple personnel changes in the band. They are widely considered to be one of the first hardcore punk bands as well as one of the pioneers of post-hardcore. After breaking up in 1986, Black Flag reunited in 2003 and again in 2013.
Despite 1984-85 being the most fruitful period for the band and their record label, Ginn and Rollins would ultimately decide to eject Roessler from Black Flag, citing erratic behavior. It has also been suggested that Ginn's accommodating Roessler's college schedule created tension in the band. Her absence, and the lack of a steady drummer (Stevenson quit and was replaced by Anthony Martinez), contributed to the comparatively weak reputation of the last few Black Flag tours. However, the live album Who's Got the 10 1/2 ? shows the evolving line-up, with Kira and drummer Martinez, to be a powerful and entertaining unit. Furthermore, various bootlegs of shows circulating from the 1986 tour, as well as the Dave Markey documentary Reality 86'd, show the Ginn/Rollins/Revuelta/Martinez lineup to be a ferocious and cohesive group. By 1986, Black Flag's members had grown tired of the tensions of their relentless touring schedule, infighting, and of living in near-poverty. The band had been together almost a decade, and true commercial success and stability had eluded them. The band's erratic artistic changes were a barrier to their retaining an audience - Ginn was so creatively restless that Black Flag's albums were often very dissimilar. At one point, Rollins apparently said, "Why don't we make a record that was like the last one so people won't always be trying to catch up with what we're doing?" The next album, In My Head, with its powerful bluesy proto-grunge-metal, did seem to finally be a cohesive follow-up to their previous album Loose Nut, but it would be their last. Black Flag played its final show on June 27, 1986, in Detroit, Michigan. In his book Get in the Van, Rollins wrote that Ginn telephoned him in August 1986: "He told me he was quitting the band. I thought that was strange considering it was his band and all. So in one short phone call, it was all over."

What did they do next?

Black Flag played its final show on June 27, 1986, in Detroit, Michigan.

IN: Petty was born October 20, 1950, in Gainesville, Florida, the first of two sons of Kitty (nee Avery), a local tax office worker, and Earl Petty, who worked in a grocery store. He had a brother, Bruce, who was seven years younger. His interest in rock and roll music began at age ten when he met Elvis Presley. In the summer of 1961, his uncle was working on the set of Presley's film Follow That Dream, in nearby Ocala, and invited Petty to watch the shoot.

Petty's first appearance in film took place in 1978, when he had a cameo in FM. He later had a small part in 1987's Made in Heaven and appeared in several episodes of It's Garry Shandling's Show between 1987 and 1990, playing himself as one of Garry Shandling's neighbors. Petty was also featured in Shandling's other show, The Larry Sanders Show, as one of the Story within a story final guests. In the episode, Petty gets bumped from the show and nearly comes to blows with Greg Kinnear. Petty appeared in the 1997 film The Postman, directed by and starring Kevin Costner, as the Bridge City Mayor (from the dialogue it is implied that he is playing a future history version of himself). In 2002, he appeared on The Simpsons in the episode "How I Spent My Strummer Vacation", along with Mick Jagger, Keith Richards, Lenny Kravitz, Elvis Costello, and Brian Setzer. In it, Petty spoofed himself as a tutor to Homer Simpson on the art of lyric writing, composing a brief song about a drunk girl driving down the road while concerned with the state of public schools. Later in the episode, he loses a toe during a riot. Petty had a recurring role as the voice of Elroy "Lucky" Kleinschmidt in the animated comedy series King of the Hill from 2004 to 2009. In 2010, Petty made a five-second cameo appearance with comedian Andy Samberg in a musical video titled "Great Day" featured on the bonus DVD as part of The Lonely Island's new album Turtleneck & Chain.

Did he do any other acting?

OUT:
He later had a small part in 1987's Made in Heaven and appeared in several episodes of It's Garry Shandling's Show