Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/42130 )
Change subject: superio/nuvoton: Build hwm.c for all stages ......................................................................
Patch Set 1:
(1 comment)
https://review.coreboot.org/c/coreboot/+/42130/1//COMMIT_MSG Commit Message:
https://review.coreboot.org/c/coreboot/+/42130/1//COMMIT_MSG@9 PS1, Line 9: There's no reason
IMO, HWM configuration is best done in the ramstage via devicetree. Any […]
The original idea was to ramp up the fans to full speed until raminit is done, then lower them to half speed and engage automatic control. That makes this function necessary in stages other than ramstage. Another idea was to ramp up the fans to full speed if coreboot dies, and since coreboot can die in any stage...
Note that I'm currently trying things out, so it's not a definite approach yet. For fan control stuff, I wanted to allow configurability (e.g. with a CBFS file that contains the fan control parameters), which is not really doable if putting values in the devicetree. And yes, configurability is needed: not everyone will use this B85M Pro4 with an [AVC DA09025T12U] as CPU fan.
[AVC DA09025T12U]: A 12V 0.70A fan, which sounds like a hair dryer at full speed: https://www.dhresource.com/0x0/f2/albu/g8/M01/D4/25/rBVaV1yQtRWAORKLAATr_7Qe...