serve one's turn
meet one's need, answer one's requirements
LLL I.i.285 [King to Costard] This 'maid' will not serve your turn [i.e. get you out of trouble; pun: 286]
TC III.i.72 [Pandarus to Helen, of her witty response] that shall not serve your turn
Tim II.i.20 [Senator to Caphis, of Timon] I must serve my turn / Out of mine own [i.e. resources]
TS IV.ii.62 [Biondello to Tranio] I spied / An ancient angel ... / Will serve the turn