Jonathan Kollasch has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/41687 )
Change subject: mb/supermicro/x9scl: Select IPMI_KCS ......................................................................
Patch Set 1: Code-Review-1
Have you tested this on a X9SCL or X9SCM (i.e. one without BMC features)?
The reason I didn't enable this already was that it caused rather long delays in boot time (on the order of like 30 seconds or more, IIRC) on a X9SCL, as the unimplemented BMC never came ready. That said, it did appear to work OK when I tried it on the X9SCM-F.
I think there's a board config strap GPIO that indicates the presence of BMC features, but I have not identified it exactly.