People have missed this quest by either killing the trolls or talking to Reginald before talking to Homer, but once it is given I don't recall any problems completing it.
Did you kill all the trolls? There are usually a couple off in the eastern or south eastern parts of the cave that do not attack with the rest.
How long did you wait before returning to Homer? Perhaps doing something else can break the speech option.
Can you ask about the trolls at all (or his farm again)? Maybe if you go through all the available speech options, exit and talk to him again it might help.
You should be able to say something like 'you know that troll problem you -used- to have...' to solve the quest.
Depending on why you do not get the required dialog option with Homer, it may be possible to use the procedure in the following topic to complete the quest.
FIX for broken Imp Council Member questYou will need my
dialog file (13KB), from a save after killing the trolls, but before talking to Homer.