You do not need to configure a relay or "ip helper-address" on the controller if:
- The default gateway of the client VLAN already has an ip address
- The DHCP server is on the same VLAN as the client VLAN
- The controller is providing DHCP server for the client VLAN
If the above 3 are not the case, you need to make sure:
- The controller has an ip interface on that VLAN, AND you put a helper-address on that IP interface pointing to the DHCP server or
- The controller is bridging traffic to a VLAN that already has a helper address configured or
- The DHCP server is on the same VLAN as the client.