Not all umpires ignore call to quit (6)
I believe the answer is:
resign
'quit' is the definition.
(resigning is a kind of quiting)
'not all umpires ignore call' is the wordplay.
'not all' indicates the answer is hidden within the clue.
'RESIGN' is hidden in the letters of 'umpires ignore call'.
'to' is the link.
(Other definitions for resign that I've seen before include "admit defeat" , "Give up one's post" , "Step down" , "advice for the incompetent?" , "Give up one's job" .)