For AOC-STG-b4S, is the chipset natively supported in kernel ver x.y.z and newer, or does it require a separate driver module? If it's a separate driver module, would it come from the vendor or SMC?
There are drivers for kernels from 2.4.24 to 2.6.16; iSCSI offload is only supported on 2.6.16. You can find drivers on link below.
https://www.supermicro.com/wdl/driver/Broadcom/