.\" .\" Copyright (c) 2012 Sean Bruno .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD: head/share/man/man4/est.4 267938 2014-06-26 21:46:14Z bapt $ .\" .Dd October 18, 2012 .Dt EST 4 .Os .Sh NAME .Nm est .Nd Enhanced Speedstep Technology .Sh SYNOPSIS To compile this capability into your kernel place the following line in your kernel configuration file: .Bd -ragged -offset indent .Cd "device cpufreq" .Ed .Sh DESCRIPTION The .Nm interface provides support for the Intel Enhanced Speedstep Technology. .Pp Note that .Nm capabilities are automatically loaded by the .Xr cpufreq 4 driver. .Sh LOADER TUNABLES The .Nm interface is intended to allow .Xr cpufreq 4 to access and implement Intel Enhanced SpeedStep Technology via .Xr acpi 4 and the acpi_perf interface accessors. If the default settings are not optimal, the following sysctls can be used to modify or monitor .Nm behavior. .Bl -tag -width indent .It hw.est.msr_info Attempt to infer information from direct probing of the msr. Should only be used in diagnostic cases. .Pq default 0 .It hw.est.strict Validate frequency requested is accepted by the cpu when set. It appears that this will only work on single core cpus. .Pq default 0 .El .Sh SYSCTL VARIABLES The following .Xr sysctl 8 values are available .Bl -tag -width indent .It Va dev.est.%d.\%desc Description of support, almost always Enhanced SpeedStep Frequency Control. .It dev.est.0.%desc: Enhanced SpeedStep Frequency Control .It Va dev.est.%d.\%driver Driver in use, always est. .It dev.est.0.%driver: est .It Va dev.est.%d.\%parent .It dev.est.0.%parent: cpu0 The cpu that is exposing these frequencies. For example .Va cpu0 . .It Va dev.est.%d.freq_settings . The valid frequencies that are allowed by this CPU and their step values. .It dev.est.0.freq_settings: 2201/45000 2200/45000 2000/39581 1900/37387 1800/34806 1700/32703 1600/30227 1500/28212 1400/25828 1300/23900 1200/21613 1100/19775 1000/17582 900/15437 800/13723 .El .Sh DIAGNOSTICS .Bl -diag .It "est%d: on cpu%d" .Pp Indicates normal startup of this interface. .It "est: CPU supports Enhanced Speedstep, but is not recognized." .It "est: cpu_vendor GenuineIntel, msr 471c471c0600471c" .It "device_attach: est%d attach returned 6" .Pp Indicates all attempts to attach to this interface have failed. This usually indicates an improper BIOS setting restricting O/S control of the CPU speeds. Consult your BIOS documentation for more details. .El .Sh COMPATIBILITY .Nm is only found on supported Intel CPUs. .Sh SEE ALSO .Xr cpufreq 4 .Rs .%T "Intel 64 and IA-32 Architectures Software Developer Manuals" .%U "http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html" .Re .Sh AUTHORS This manual page was written by .An Sean Bruno Aq Mt sbruno@FreeBSD.org .