Though upset, call for dismissal (6)
I believe the answer is:
firing
'dismissal' is the definition.
(I know that dismissal can be written as firing)
'though upset call' is the wordplay.
'though' becomes 'if' (I've seen this in other clues).
'upset' is a reversal indicator.
'call' becomes 'ring' (telephone call).
'if' written backwards gives 'fi'.
'fi'+'ring'='FIRING'
'for' is the link.
(Other definitions for firing that I've seen before include "Discharging a gun" , "Dismissal" , "Shooting; sacking" , "Dismissing" , "Discharging, sacking" .)