CPU frequency scaling driver for VIA C7 Esther (mini-ITX)

blandoon

I'm compiling a kernel for a VIA EPIA CN10000 board with the C7 "Esther" CPU, and I want to enable CPU frequency scaling, but I don't know which driver I need to work with the VIA processor. I've seen references elsewhere to the "longhaul" driver, but it doesn't seem to be available in the current kernel (2.6.17-r

. Which kernel options do I need to get cpufreqd, or similar, to work?
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tomatopi · Posted: Tue Oct 10, 2006 6:42 pm Post subject:

Last I heard Longhaul was broken and missing a maintainer so was removed from the kernel. Somebody correct me if I'm wrong. I've got quite a few Via EPIA's I'd like to get Longhaul working on, too.

blandoon · Posted: Wed Oct 11, 2006 6:06 pm Post subject:

Wow, that's pretty weak... I'd offer to help, but I'm no developer (certainly not to the extent required for something like that).

Is there any other good way of getting frequency scaling to work on the C3 family of processors?
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"Give a man a fire and he's warm for one night, but set fire to him and he's warm for the rest of his life..."

tomatopi · Posted: Wed Oct 11, 2006 6:34 pm Post subject:

From what I've heard, it is possible to patch the existing kernel to get LongHaul working as it was in the last official release, but it is still broken. I know on some of my boards, it would hang if the system changed frequencies too often or too fast. Other machines where fine, but it was rather unpredictable.

There's a discussion at VIA Arena about it. Search the Linux forum for longhaul and you'll get quite a bit of info.

From what I've read from some people's testing, those CPU's use so little power, the CPU throttling didn't actually save very much.