In 1980, Farmer was selected to play in the All-Star Game at Dodger Stadium. He face three batters, recording the final two outs of the sixth inning when he got Pete Rose to ground into a double play. Farmer compiled 18 saves prior to the break, and finished the season with career highs in saves (30) and wins (7). He took the White Sox to arbitration in 1981, asking for $495,000 while the team offered $300,000. The arbitrator picked Farmer's number. Jim Palmer cited this as an example of the reason for rising salaries in the major leagues: "Since the owners kept paying more and more to mediocre players, the averages kept going up and the arbitrators looked at the averages and usually went with the player's number, which raised the average some more." After spending the 1981 season with the White Sox, registering three wins and 10 saves, Farmer became a free agent in November 1981. In his three seasons with the White Sox, Farmer appeared in 148 games and notched 54 saves while striking out 144 batters in innings pitched, with a 3.31 ERA.