2 # x86 CPU Frequency scaling drivers
5 config X86_INTEL_PSTATE
6 bool "Intel P state control"
9 This driver provides a P state for Intel core processors.
10 The driver implements an internal governor and will become
11 the scaling driver and governor for Sandy bridge processors.
13 When this driver is enabled it will become the preferred
14 scaling driver for Sandy bridge processors.
18 config X86_PCC_CPUFREQ
19 tristate "Processor Clocking Control interface driver"
20 depends on ACPI && ACPI_PROCESSOR
22 This driver adds support for the PCC interface.
24 For details, take a look at:
25 <file:Documentation/cpu-freq/pcc-cpufreq.txt>.
27 To compile this driver as a module, choose M here: the
28 module will be called pcc-cpufreq.
32 config X86_ACPI_CPUFREQ
33 tristate "ACPI Processor P-States driver"
34 depends on ACPI_PROCESSOR
36 This driver adds a CPUFreq driver which utilizes the ACPI
37 Processor Performance States.
38 This driver also supports Intel Enhanced Speedstep and newer
41 To compile this driver as a module, choose M here: the
42 module will be called acpi-cpufreq.
44 For details, take a look at <file:Documentation/cpu-freq/>.
48 config X86_ACPI_CPUFREQ_CPB
50 bool "Legacy cpb sysfs knob support for AMD CPUs"
51 depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD
53 The powernow-k8 driver used to provide a sysfs knob called "cpb"
54 to disable the Core Performance Boosting feature of AMD CPUs. This
55 file has now been superseded by the more generic "boost" entry.
57 By enabling this option the acpi_cpufreq driver provides the old
58 entry in addition to the new boost ones, for compatibility reasons.
61 tristate "AMD Elan SC400 and SC410"
64 This adds the CPUFreq driver for AMD Elan SC400 and SC410
67 You need to specify the processor maximum speed as boot
68 parameter: elanfreq=maxspeed (in kHz) or as module
71 For details, take a look at <file:Documentation/cpu-freq/>.
76 tristate "AMD Elan SC520"
79 This adds the CPUFreq driver for AMD Elan SC520 processor.
81 For details, take a look at <file:Documentation/cpu-freq/>.
86 config X86_POWERNOW_K6
87 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
90 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
93 For details, take a look at <file:Documentation/cpu-freq/>.
97 config X86_POWERNOW_K7
98 tristate "AMD Mobile Athlon/Duron PowerNow!"
101 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
103 For details, take a look at <file:Documentation/cpu-freq/>.
107 config X86_POWERNOW_K7_ACPI
109 depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
110 depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
114 config X86_POWERNOW_K8
115 tristate "AMD Opteron/Athlon64 PowerNow!"
116 depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
118 This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
119 Support for K10 and newer processors is now in acpi-cpufreq.
121 To compile this driver as a module, choose M here: the
122 module will be called powernow-k8.
124 For details, take a look at <file:Documentation/cpu-freq/>.
126 config X86_AMD_FREQ_SENSITIVITY
127 tristate "AMD frequency sensitivity feedback powersave bias"
128 depends on CPU_FREQ_GOV_ONDEMAND && X86_ACPI_CPUFREQ && CPU_SUP_AMD
130 This adds AMD-specific powersave bias function to the ondemand
131 governor, which allows it to make more power-conscious frequency
132 change decisions based on feedback from hardware (available on AMD
133 Family 16h and above).
135 Hardware feedback tells software how "sensitive" to frequency changes
136 the CPUs' workloads are. CPU-bound workloads will be more sensitive
137 -- they will perform better as frequency increases. Memory/IO-bound
138 workloads will be less sensitive -- they will not necessarily perform
139 better as frequency increases.
143 config X86_GX_SUSPMOD
144 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
145 depends on X86_32 && PCI
147 This add the CPUFreq driver for NatSemi Geode processors which
148 support suspend modulation.
150 For details, take a look at <file:Documentation/cpu-freq/>.
154 config X86_SPEEDSTEP_CENTRINO
155 tristate "Intel Enhanced SpeedStep (deprecated)"
156 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
157 depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
159 This is deprecated and this functionality is now merged into
160 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
162 This adds the CPUFreq driver for Enhanced SpeedStep enabled
163 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
164 or 64bit enabled Intel Xeons.
166 To compile this driver as a module, choose M here: the
167 module will be called speedstep-centrino.
169 For details, take a look at <file:Documentation/cpu-freq/>.
173 config X86_SPEEDSTEP_CENTRINO_TABLE
174 bool "Built-in tables for Banias CPUs"
175 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
178 Use built-in tables for Banias CPUs if ACPI encoding
183 config X86_SPEEDSTEP_ICH
184 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
187 This adds the CPUFreq driver for certain mobile Intel Pentium III
188 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
189 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
190 ICH3 or ICH4 southbridge.
192 For details, take a look at <file:Documentation/cpu-freq/>.
196 config X86_SPEEDSTEP_SMI
197 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
200 This adds the CPUFreq driver for certain mobile Intel Pentium III
201 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
202 on systems which have an Intel 440BX/ZX/MX southbridge.
204 For details, take a look at <file:Documentation/cpu-freq/>.
208 config X86_P4_CLOCKMOD
209 tristate "Intel Pentium 4 clock modulation"
211 This adds the CPUFreq driver for Intel Pentium 4 / XEON
212 processors. When enabled it will lower CPU temperature by skipping
215 This driver should be only used in exceptional
216 circumstances when very low power is needed because it causes severe
217 slowdowns and noticeable latencies. Normally Speedstep should be used
220 To compile this driver as a module, choose M here: the
221 module will be called p4-clockmod.
223 For details, take a look at <file:Documentation/cpu-freq/>.
225 Unless you are absolutely sure say N.
227 config X86_CPUFREQ_NFORCE2
228 tristate "nVidia nForce2 FSB changing"
231 This adds the CPUFreq driver for FSB changing on nVidia nForce2
234 For details, take a look at <file:Documentation/cpu-freq/>.
239 tristate "Transmeta LongRun"
242 This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
243 which support LongRun.
245 For details, take a look at <file:Documentation/cpu-freq/>.
250 tristate "VIA Cyrix III Longhaul"
251 depends on X86_32 && ACPI_PROCESSOR
253 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
254 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
257 For details, take a look at <file:Documentation/cpu-freq/>.
261 config X86_E_POWERSAVER
262 tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)"
263 depends on X86_32 && ACPI_PROCESSOR
265 This adds the CPUFreq driver for VIA C7 processors. However, this driver
266 does not have any safeguards to prevent operating the CPU out of spec
267 and is thus considered dangerous. Please use the regular ACPI cpufreq
268 driver, enabled by CONFIG_X86_ACPI_CPUFREQ.
272 comment "shared options"
274 config X86_SPEEDSTEP_LIB
276 default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
278 config X86_SPEEDSTEP_RELAXED_CAP_CHECK
279 bool "Relaxed speedstep capability checks"
280 depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
282 Don't perform all checks for a speedstep capable system which would
283 normally be done. Some ancient or strange systems, though speedstep
284 capable, don't always indicate that they are speedstep capable. This
285 option lets the probing code bypass some of those checks if the
286 parameter "relaxed_check=1" is passed to the module.