FreeBSD : fan control on a tyan motherboard with w83793-i2c sensors

Question

This question is tightly linked to : Safe FreeBSD test on system running debian with zpools

I have a quite exotic (I mean not an HP or Dell etc...) tyan motherboard with a bad regulation system. I can make my way with it under linux with pwncontrol.

During the time I accepted enduring the noise I tried a few things, but I felt like reading fan speed and writing fan power was quite impossible. It uses a winbond sensor chipset : w83793-i2c-0-2f. Coretemp info where available

This hardware is from 2010 and is server hardware so I assumed it would not be a problem to run freebsd on it.

Does anyone encounter the same issues ? I've heard of mbmon and healthd but if I can't access the device, what's there to regulate?

I guess the answer : this hardware is not supported, deal with it would be acceptable as long it's the reality.

I'm also aware of electrical solutions to hack the supplied voltage to the fan but I'd rather avoid that

Answer 1

The W83793G is a relatively new device, and is definitely not supported by xmbmon 205 or healthd 0.7.9, both of which haven't been updated in any meaningful way since 2004.

This device, however, is supported on OpenBSD since 4.3 (2007/2008) with wbng(4) — http://bxr.su/o/sys/dev/i2c/w83793g.c, although only the monitoring bits are supported, without fan control. Having a hack to do fan control should be easy enough, though. Not other BSD system appears to support W83793G.

One trick you could possibly use is configuring the chip through BIOS, or configure it from Linux, then reboot back into FreeBSD (provided the BIOS wouldn't reset the settings in the chip). Else, best course of action might be to hack the support yourself, or find someone who could do it for you. Disclaimer: I'm the author of the driver above. :-)