# # CPU Frequency scaling # menu "CPU Frequency scaling" source "drivers/cpufreq/Kconfig" if CPU_FREQ comment "CPUFreq processor drivers" config X86_ACPI_CPUFREQ tristate "ACPI Processor P-States driver" select CPU_FREQ_TABLE 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. To compile this driver as a module, choose M here: the module will be called acpi-cpufreq. For details, take a look at . If in doubt, say N. config ELAN_CPUFREQ tristate "AMD Elan SC400 and SC410" select CPU_FREQ_TABLE depends on X86_ELAN ---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 . If in doubt, say N. config SC520_CPUFREQ tristate "AMD Elan SC520" select CPU_FREQ_TABLE depends on X86_ELAN ---help--- This adds the CPUFreq driver for AMD Elan SC520 processor. For details, take a look at . If in doubt, say N. config X86_POWERNOW_K6 tristate "AMD Mobile K6-2/K6-3 PowerNow!" select CPU_FREQ_TABLE 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 . If in doubt, say N. config X86_POWERNOW_K7 tristate "AMD Mobile Athlon/Duron PowerNow!" select CPU_FREQ_TABLE depends on X86_32 help This adds the CPUFreq driver for mobile AMD K7 mobile processors. For details, take a look at . 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!" select CPU_FREQ_TABLE help This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors. To compile this driver as a module, choose M here: the module will be called powernow-k8. For details, take a look at . If in doubt, say N. config X86_POWERNOW_K8_ACPI bool prompt "ACPI Support" if X86_32 depends on ACPI && X86_POWERNOW_K8 && ACPI_PROCESSOR depends on !(X86_POWERNOW_K8 = y && ACPI_PROCESSOR = m) default y help This provides access to the K8s Processor Performance States via ACPI. This driver is probably required for CPUFreq to work with multi-socket and SMP systems. It is not required on at least some single-socket yet multi-core systems, even if SMP is enabled. It is safe to say Y here. 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 . If in doubt, say N. config X86_SPEEDSTEP_CENTRINO tristate "Intel Enhanced SpeedStep (deprecated)" select CPU_FREQ_TABLE 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 . 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)" select CPU_FREQ_TABLE 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 . If in doubt, say N. config X86_SPEEDSTEP_SMI tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)" select CPU_FREQ_TABLE depends on X86_32 && EXPERIMENTAL 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 . If in doubt, say N. config X86_P4_CLOCKMOD tristate "Intel Pentium 4 clock modulation" select CPU_FREQ_TABLE 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 . Unless you are absolutely sure say N. config X86_CPUFREQ_NFORCE2 tristate "nVidia nForce2 FSB changing" depends on X86_32 && EXPERIMENTAL help This adds the CPUFreq driver for FSB changing on nVidia nForce2 platforms. For details, take a look at . 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 . If in doubt, say N. config X86_LONGHAUL tristate "VIA Cyrix III Longhaul" select CPU_FREQ_TABLE 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 . If in doubt, say N. config X86_E_POWERSAVER tristate "VIA C7 Enhanced PowerSaver" select CPU_FREQ_TABLE depends on X86_32 help This adds the CPUFreq driver for VIA C7 processors. If in doubt, say N. comment "shared options" config X86_ACPI_CPUFREQ_PROC_INTF bool "/proc/acpi/processor/../performance interface (deprecated)" depends on PROC_FS depends on X86_ACPI_CPUFREQ || X86_POWERNOW_K7_ACPI || X86_POWERNOW_K8_ACPI help This enables the deprecated /proc/acpi/processor/../performance interface. While it is helpful for debugging, the generic, cross-architecture cpufreq interfaces should be used. If in doubt, say N. 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. endif # CPU_FREQ endmenu