Edit File: Kconfig.x86
# # x86 CPU Frequency scaling drivers # config X86_INTEL_PSTATE bool "Intel P state control" depends on X86 select ACPI_PROCESSOR if ACPI select ACPI_CPPC_LIB if X86_64 && ACPI && SCHED_MC_PRIO help This driver provides a P state for Intel core processors. The driver implements an internal governor and will become the scaling driver and governor for Sandy bridge processors. When this driver is enabled it will become the preferred scaling driver for Sandy bridge processors. If in doubt, say N. config X86_PCC_CPUFREQ tristate "Processor Clocking Control interface driver" depends on ACPI && ACPI_PROCESSOR help This driver adds support for the PCC interface. For details, take a look at: <file:Documentation/cpu-freq/pcc-cpufreq.txt>. To compile this driver as a module, choose M here: the module will be called pcc-cpufreq. If in doubt, say N. config X86_ACPI_CPUFREQ tristate "ACPI Processor P-States driver" depends on ACPI_PROCESSOR help This driver adds a CPUFreq driver which utilizes the ACPI Processor Performance States. This driver also supports Intel Enhanced Speedstep and newer AMD CPUs. To compile this driver as a module, choose M here: the module will be called acpi-cpufreq. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_ACPI_CPUFREQ_CPB default y bool "Legacy cpb sysfs knob support for AMD CPUs" depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD help The powernow-k8 driver used to provide a sysfs knob called "cpb" to disable the Core Performance Boosting feature of AMD CPUs. This file has now been superseded by the more generic "boost" entry. By enabling this option the acpi_cpufreq driver provides the old entry in addition to the new boost ones, for compatibility reasons. config ELAN_CPUFREQ tristate "AMD Elan SC400 and SC410" depends on MELAN ---help--- This adds the CPUFreq driver for AMD Elan SC400 and SC410 processors. You need to specify the processor maximum speed as boot parameter: elanfreq=maxspeed (in kHz) or as module parameter "max_freq". For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config SC520_CPUFREQ tristate "AMD Elan SC520" depends on MELAN ---help--- This adds the CPUFreq driver for AMD Elan SC520 processor. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_POWERNOW_K6 tristate "AMD Mobile K6-2/K6-3 PowerNow!" depends on X86_32 help This adds the CPUFreq driver for mobile AMD K6-2+ and mobile AMD K6-3+ processors. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_POWERNOW_K7 tristate "AMD Mobile Athlon/Duron PowerNow!" depends on X86_32 help This adds the CPUFreq driver for mobile AMD K7 mobile processors. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_POWERNOW_K7_ACPI bool depends on X86_POWERNOW_K7 && ACPI_PROCESSOR depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m) depends on X86_32 default y config X86_POWERNOW_K8 tristate "AMD Opteron/Athlon64 PowerNow!" depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ help This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors. Support for K10 and newer processors is now in acpi-cpufreq. To compile this driver as a module, choose M here: the module will be called powernow-k8. For details, take a look at <file:Documentation/cpu-freq/>. config X86_AMD_FREQ_SENSITIVITY tristate "AMD frequency sensitivity feedback powersave bias" depends on CPU_FREQ_GOV_ONDEMAND && X86_ACPI_CPUFREQ && CPU_SUP_AMD help This adds AMD-specific powersave bias function to the ondemand governor, which allows it to make more power-conscious frequency change decisions based on feedback from hardware (available on AMD Family 16h and above). Hardware feedback tells software how "sensitive" to frequency changes the CPUs' workloads are. CPU-bound workloads will be more sensitive -- they will perform better as frequency increases. Memory/IO-bound workloads will be less sensitive -- they will not necessarily perform better as frequency increases. If in doubt, say N. config X86_GX_SUSPMOD tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation" depends on X86_32 && PCI help This add the CPUFreq driver for NatSemi Geode processors which support suspend modulation. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_SPEEDSTEP_CENTRINO tristate "Intel Enhanced SpeedStep (deprecated)" select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32 depends on X86_32 || (X86_64 && ACPI_PROCESSOR) help This is deprecated and this functionality is now merged into acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of speedstep_centrino. This adds the CPUFreq driver for Enhanced SpeedStep enabled mobile CPUs. This means Intel Pentium M (Centrino) CPUs or 64bit enabled Intel Xeons. To compile this driver as a module, choose M here: the module will be called speedstep-centrino. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_SPEEDSTEP_CENTRINO_TABLE bool "Built-in tables for Banias CPUs" depends on X86_32 && X86_SPEEDSTEP_CENTRINO default y help Use built-in tables for Banias CPUs if ACPI encoding is not available. If in doubt, say N. config X86_SPEEDSTEP_ICH tristate "Intel Speedstep on ICH-M chipsets (ioport interface)" depends on X86_32 help This adds the CPUFreq driver for certain mobile Intel Pentium III (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2, ICH3 or ICH4 southbridge. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_SPEEDSTEP_SMI tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)" depends on X86_32 help This adds the CPUFreq driver for certain mobile Intel Pentium III (Coppermine), all mobile Intel Pentium III-M (Tualatin) on systems which have an Intel 440BX/ZX/MX southbridge. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_P4_CLOCKMOD tristate "Intel Pentium 4 clock modulation" help This adds the CPUFreq driver for Intel Pentium 4 / XEON processors. When enabled it will lower CPU temperature by skipping clocks. This driver should be only used in exceptional circumstances when very low power is needed because it causes severe slowdowns and noticeable latencies. Normally Speedstep should be used instead. To compile this driver as a module, choose M here: the module will be called p4-clockmod. For details, take a look at <file:Documentation/cpu-freq/>. Unless you are absolutely sure say N. config X86_CPUFREQ_NFORCE2 tristate "nVidia nForce2 FSB changing" depends on X86_32 help This adds the CPUFreq driver for FSB changing on nVidia nForce2 platforms. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_LONGRUN tristate "Transmeta LongRun" depends on X86_32 help This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors which support LongRun. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_LONGHAUL tristate "VIA Cyrix III Longhaul" depends on X86_32 && ACPI_PROCESSOR help This adds the CPUFreq driver for VIA Samuel/CyrixIII, VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T processors. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N. config X86_E_POWERSAVER tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)" depends on X86_32 && ACPI_PROCESSOR help This adds the CPUFreq driver for VIA C7 processors. However, this driver does not have any safeguards to prevent operating the CPU out of spec and is thus considered dangerous. Please use the regular ACPI cpufreq driver, enabled by CONFIG_X86_ACPI_CPUFREQ. If in doubt, say N. comment "shared options" config X86_SPEEDSTEP_LIB tristate default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD) config X86_SPEEDSTEP_RELAXED_CAP_CHECK bool "Relaxed speedstep capability checks" depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH) help Don't perform all checks for a speedstep capable system which would normally be done. Some ancient or strange systems, though speedstep capable, don't always indicate that they are speedstep capable. This option lets the probing code bypass some of those checks if the parameter "relaxed_check=1" is passed to the module.