Bug 242166 - cpufreq can't be loaded on old cpus and some new (such with LGA775) without hint.p4tcc.0.disabled=0
Summary: cpufreq can't be loaded on old cpus and some new (such with LGA775) without h...
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 12.1-RELEASE
Hardware: amd64 Any
: --- Affects Some People
Assignee: freebsd-bugs (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-11-23 03:43 UTC by sasamotikomi
Modified: 2019-11-23 03:43 UTC (History)
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Description sasamotikomi 2019-11-23 03:43:28 UTC 
Only with hint.p4tcc.0.disabled=0 in loader.conf frequency can be loaded and changed on celeron 430.
Sysctl output with hint.p4tcc.0.disabled=0 in loader.conf
$ sysctl dev.cpu.0.freq_levels
dev.cpu.0.freq_levels: 1814/-1 1587/-1 1360/-1 1133/-1 907/-1 680/-1 453/-1 226/-1
Probably as well almost on all without C-state or not supported with C-state CPU  by FreeBSD from 2000-2010.
P4TCC obviously haven't support voltage changing, so we need more modern replacement or at least enable p4tcc by default on not supported CPU as temporarily solution.