You should seriously consider the application of drywall primer to fix patches. Depending on the size of the area needing repair, use a paintbrush or roller to apply the primer. The purpose being to seal the joint compound and get the area ready for painting. Failing to apply primer means the repaired area will absorb multiple coats of paint.
Our painters always follow the correct process, find out more about our services here: https://www.youraucklandpainters.co.nz