Chalky's only interest at that point was trying to help Daughter Maitland and her daughter(who I believe is Chalky's) get free of Narcisse,and for Daughter to get her music career back. Once he felt that he had accomplished that,he knew that he was out of road.
Chalky was on the run ,wanted for the murder of a fellow escapee,as well as the prison guard. His daughter was dead,he had no crew left,no place to hide,and he knew that he would never win the battle against Narcisse.
Once Daughter was taken care of (in his mind) he resigned himself to his fate.
I believe that the minute he agreed to Narcisse's proposal,he knew that he wasn't leaving alive.