2 # CPU Frequency scaling
5 menu "CPU Frequency scaling"
7 source "drivers/cpufreq/Kconfig"
11 comment "CPUFreq processor drivers"
13 config X86_ACPI_CPUFREQ
14 tristate "ACPI Processor P-States driver"
16 depends on ACPI_PROCESSOR
18 This driver adds a CPUFreq driver which utilizes the ACPI
19 Processor Performance States.
20 This driver also supports Intel Enhanced Speedstep.
22 To compile this driver as a module, choose M here: the
23 module will be called acpi-cpufreq.
25 For details, take a look at <file:Documentation/cpu-freq/>.
30 tristate "AMD Elan SC400 and SC410"
34 This adds the CPUFreq driver for AMD Elan SC400 and SC410
37 You need to specify the processor maximum speed as boot
38 parameter: elanfreq=maxspeed (in kHz) or as module
41 For details, take a look at <file:Documentation/cpu-freq/>.
46 tristate "AMD Elan SC520"
50 This adds the CPUFreq driver for AMD Elan SC520 processor.
52 For details, take a look at <file:Documentation/cpu-freq/>.
57 config X86_POWERNOW_K6
58 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
62 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
65 For details, take a look at <file:Documentation/cpu-freq/>.
69 config X86_POWERNOW_K7
70 tristate "AMD Mobile Athlon/Duron PowerNow!"
74 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
76 For details, take a look at <file:Documentation/cpu-freq/>.
80 config X86_POWERNOW_K7_ACPI
82 depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
83 depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
87 config X86_POWERNOW_K8
88 tristate "AMD Opteron/Athlon64 PowerNow!"
91 This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors.
93 To compile this driver as a module, choose M here: the
94 module will be called powernow-k8.
96 For details, take a look at <file:Documentation/cpu-freq/>.
100 config X86_POWERNOW_K8_ACPI
102 prompt "ACPI Support" if X86_32
103 depends on ACPI && X86_POWERNOW_K8 && ACPI_PROCESSOR
104 depends on !(X86_POWERNOW_K8 = y && ACPI_PROCESSOR = m)
107 This provides access to the K8s Processor Performance States via ACPI.
108 This driver is probably required for CPUFreq to work with multi-socket and
109 SMP systems. It is not required on at least some single-socket yet
110 multi-core systems, even if SMP is enabled.
112 It is safe to say Y here.
114 config X86_GX_SUSPMOD
115 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
116 depends on X86_32 && PCI
118 This add the CPUFreq driver for NatSemi Geode processors which
119 support suspend modulation.
121 For details, take a look at <file:Documentation/cpu-freq/>.
125 config X86_SPEEDSTEP_CENTRINO
126 tristate "Intel Enhanced SpeedStep (deprecated)"
127 select CPU_FREQ_TABLE
128 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
129 depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
131 This is deprecated and this functionality is now merged into
132 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
134 This adds the CPUFreq driver for Enhanced SpeedStep enabled
135 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
136 or 64bit enabled Intel Xeons.
138 To compile this driver as a module, choose M here: the
139 module will be called speedstep-centrino.
141 For details, take a look at <file:Documentation/cpu-freq/>.
145 config X86_SPEEDSTEP_CENTRINO_TABLE
146 bool "Built-in tables for Banias CPUs"
147 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
150 Use built-in tables for Banias CPUs if ACPI encoding
155 config X86_SPEEDSTEP_ICH
156 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
157 select CPU_FREQ_TABLE
160 This adds the CPUFreq driver for certain mobile Intel Pentium III
161 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
162 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
163 ICH3 or ICH4 southbridge.
165 For details, take a look at <file:Documentation/cpu-freq/>.
169 config X86_SPEEDSTEP_SMI
170 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
171 select CPU_FREQ_TABLE
172 depends on X86_32 && EXPERIMENTAL
174 This adds the CPUFreq driver for certain mobile Intel Pentium III
175 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
176 on systems which have an Intel 440BX/ZX/MX southbridge.
178 For details, take a look at <file:Documentation/cpu-freq/>.
182 config X86_P4_CLOCKMOD
183 tristate "Intel Pentium 4 clock modulation"
184 select CPU_FREQ_TABLE
186 This adds the CPUFreq driver for Intel Pentium 4 / XEON
187 processors. When enabled it will lower CPU temperature by skipping
190 This driver should be only used in exceptional
191 circumstances when very low power is needed because it causes severe
192 slowdowns and noticeable latencies. Normally Speedstep should be used
195 To compile this driver as a module, choose M here: the
196 module will be called p4-clockmod.
198 For details, take a look at <file:Documentation/cpu-freq/>.
200 Unless you are absolutely sure say N.
202 config X86_CPUFREQ_NFORCE2
203 tristate "nVidia nForce2 FSB changing"
204 depends on X86_32 && EXPERIMENTAL
206 This adds the CPUFreq driver for FSB changing on nVidia nForce2
209 For details, take a look at <file:Documentation/cpu-freq/>.
214 tristate "Transmeta LongRun"
217 This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
218 which support LongRun.
220 For details, take a look at <file:Documentation/cpu-freq/>.
225 tristate "VIA Cyrix III Longhaul"
226 select CPU_FREQ_TABLE
227 depends on X86_32 && ACPI_PROCESSOR
229 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
230 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
233 For details, take a look at <file:Documentation/cpu-freq/>.
237 config X86_E_POWERSAVER
238 tristate "VIA C7 Enhanced PowerSaver"
239 select CPU_FREQ_TABLE
242 This adds the CPUFreq driver for VIA C7 processors.
246 comment "shared options"
248 config X86_ACPI_CPUFREQ_PROC_INTF
249 bool "/proc/acpi/processor/../performance interface (deprecated)"
251 depends on X86_ACPI_CPUFREQ || X86_POWERNOW_K7_ACPI || X86_POWERNOW_K8_ACPI
253 This enables the deprecated /proc/acpi/processor/../performance
254 interface. While it is helpful for debugging, the generic,
255 cross-architecture cpufreq interfaces should be used.
259 config X86_SPEEDSTEP_LIB
261 default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
263 config X86_SPEEDSTEP_RELAXED_CAP_CHECK
264 bool "Relaxed speedstep capability checks"
265 depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
267 Don't perform all checks for a speedstep capable system which would
268 normally be done. Some ancient or strange systems, though speedstep
269 capable, don't always indicate that they are speedstep capable. This
270 option lets the probing code bypass some of those checks if the
271 parameter "relaxed_check=1" is passed to the module.