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 perferred
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"
35 depends on ACPI_PROCESSOR
37 This driver adds a CPUFreq driver which utilizes the ACPI
38 Processor Performance States.
39 This driver also supports Intel Enhanced Speedstep and newer
42 To compile this driver as a module, choose M here: the
43 module will be called acpi-cpufreq.
45 For details, take a look at <file:Documentation/cpu-freq/>.
49 config X86_ACPI_CPUFREQ_CPB
51 bool "Legacy cpb sysfs knob support for AMD CPUs"
52 depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD
54 The powernow-k8 driver used to provide a sysfs knob called "cpb"
55 to disable the Core Performance Boosting feature of AMD CPUs. This
56 file has now been superseeded by the more generic "boost" entry.
58 By enabling this option the acpi_cpufreq driver provides the old
59 entry in addition to the new boost ones, for compatibility reasons.
62 tristate "AMD Elan SC400 and SC410"
66 This adds the CPUFreq driver for AMD Elan SC400 and SC410
69 You need to specify the processor maximum speed as boot
70 parameter: elanfreq=maxspeed (in kHz) or as module
73 For details, take a look at <file:Documentation/cpu-freq/>.
78 tristate "AMD Elan SC520"
82 This adds the CPUFreq driver for AMD Elan SC520 processor.
84 For details, take a look at <file:Documentation/cpu-freq/>.
89 config X86_POWERNOW_K6
90 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
94 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
97 For details, take a look at <file:Documentation/cpu-freq/>.
101 config X86_POWERNOW_K7
102 tristate "AMD Mobile Athlon/Duron PowerNow!"
103 select CPU_FREQ_TABLE
106 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
108 For details, take a look at <file:Documentation/cpu-freq/>.
112 config X86_POWERNOW_K7_ACPI
114 depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
115 depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
119 config X86_POWERNOW_K8
120 tristate "AMD Opteron/Athlon64 PowerNow!"
121 select CPU_FREQ_TABLE
122 depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
124 This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
125 Support for K10 and newer processors is now in acpi-cpufreq.
127 To compile this driver as a module, choose M here: the
128 module will be called powernow-k8.
130 For details, take a look at <file:Documentation/cpu-freq/>.
132 config X86_AMD_FREQ_SENSITIVITY
133 tristate "AMD frequency sensitivity feedback powersave bias"
134 depends on CPU_FREQ_GOV_ONDEMAND && X86_ACPI_CPUFREQ && CPU_SUP_AMD
136 This adds AMD-specific powersave bias function to the ondemand
137 governor, which allows it to make more power-conscious frequency
138 change decisions based on feedback from hardware (availble on AMD
139 Family 16h and above).
141 Hardware feedback tells software how "sensitive" to frequency changes
142 the CPUs' workloads are. CPU-bound workloads will be more sensitive
143 -- they will perform better as frequency increases. Memory/IO-bound
144 workloads will be less sensitive -- they will not necessarily perform
145 better as frequency increases.
149 config X86_GX_SUSPMOD
150 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
151 depends on X86_32 && PCI
153 This add the CPUFreq driver for NatSemi Geode processors which
154 support suspend modulation.
156 For details, take a look at <file:Documentation/cpu-freq/>.
160 config X86_SPEEDSTEP_CENTRINO
161 tristate "Intel Enhanced SpeedStep (deprecated)"
162 select CPU_FREQ_TABLE
163 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
164 depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
166 This is deprecated and this functionality is now merged into
167 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
169 This adds the CPUFreq driver for Enhanced SpeedStep enabled
170 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
171 or 64bit enabled Intel Xeons.
173 To compile this driver as a module, choose M here: the
174 module will be called speedstep-centrino.
176 For details, take a look at <file:Documentation/cpu-freq/>.
180 config X86_SPEEDSTEP_CENTRINO_TABLE
181 bool "Built-in tables for Banias CPUs"
182 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
185 Use built-in tables for Banias CPUs if ACPI encoding
190 config X86_SPEEDSTEP_ICH
191 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
192 select CPU_FREQ_TABLE
195 This adds the CPUFreq driver for certain mobile Intel Pentium III
196 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
197 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
198 ICH3 or ICH4 southbridge.
200 For details, take a look at <file:Documentation/cpu-freq/>.
204 config X86_SPEEDSTEP_SMI
205 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
206 select CPU_FREQ_TABLE
209 This adds the CPUFreq driver for certain mobile Intel Pentium III
210 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
211 on systems which have an Intel 440BX/ZX/MX southbridge.
213 For details, take a look at <file:Documentation/cpu-freq/>.
217 config X86_P4_CLOCKMOD
218 tristate "Intel Pentium 4 clock modulation"
219 select CPU_FREQ_TABLE
221 This adds the CPUFreq driver for Intel Pentium 4 / XEON
222 processors. When enabled it will lower CPU temperature by skipping
225 This driver should be only used in exceptional
226 circumstances when very low power is needed because it causes severe
227 slowdowns and noticeable latencies. Normally Speedstep should be used
230 To compile this driver as a module, choose M here: the
231 module will be called p4-clockmod.
233 For details, take a look at <file:Documentation/cpu-freq/>.
235 Unless you are absolutely sure say N.
237 config X86_CPUFREQ_NFORCE2
238 tristate "nVidia nForce2 FSB changing"
241 This adds the CPUFreq driver for FSB changing on nVidia nForce2
244 For details, take a look at <file:Documentation/cpu-freq/>.
249 tristate "Transmeta LongRun"
252 This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
253 which support LongRun.
255 For details, take a look at <file:Documentation/cpu-freq/>.
260 tristate "VIA Cyrix III Longhaul"
261 select CPU_FREQ_TABLE
262 depends on X86_32 && ACPI_PROCESSOR
264 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
265 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
268 For details, take a look at <file:Documentation/cpu-freq/>.
272 config X86_E_POWERSAVER
273 tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)"
274 select CPU_FREQ_TABLE
277 This adds the CPUFreq driver for VIA C7 processors. However, this driver
278 does not have any safeguards to prevent operating the CPU out of spec
279 and is thus considered dangerous. Please use the regular ACPI cpufreq
280 driver, enabled by CONFIG_X86_ACPI_CPUFREQ.
284 comment "shared options"
286 config X86_SPEEDSTEP_LIB
288 default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
290 config X86_SPEEDSTEP_RELAXED_CAP_CHECK
291 bool "Relaxed speedstep capability checks"
292 depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
294 Don't perform all checks for a speedstep capable system which would
295 normally be done. Some ancient or strange systems, though speedstep
296 capable, don't always indicate that they are speedstep capable. This
297 option lets the probing code bypass some of those checks if the
298 parameter "relaxed_check=1" is passed to the module.