Attention is currently required from: Paul Menzel, Varshit Pandya.
Máté Kukri has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/81529?usp=email )
Change subject: mb/dell/optiplex_9020: Implement late HWM initialization ......................................................................
Patch Set 6:
(2 comments)
File src/mainboard/dell/optiplex_9020/mainboard.c:
https://review.coreboot.org/c/coreboot/+/81529/comment/0f3802c2_8da6e256 : PS6, Line 32: struct hwm_tab_entry HWM_TAB3[] = {
Looks like they were extracted as-is from vendor firmware.
These were produced to match the values programmed by the vendor firmware.
These are a purely factual description of the fan control profiles.
All the actual logic is embedded in the EC.
File src/mainboard/dell/optiplex_9020/sch5555_ec.c:
https://review.coreboot.org/c/coreboot/+/81529/comment/fec83446_76cdb3b8 : PS6, Line 25: for (size_t timeout = 0; timeout < 0xfff; ++timeout)
There's no time delay in this code. […]
Perhaps "timeout" as a loop counter is slightly misleading.
Having no actual delay here is intended, this code is meant to poll the specific I/O port until the EC ACKs the message. This usually happens in <20 iterations.