Linux 3.12.39
[linux/fpc-iii.git] / drivers / cpufreq / Kconfig.x86
blobe2b6eabef2218d4e1e392ed523b3451553e196cb
2 # x86 CPU Frequency scaling drivers
5 config X86_INTEL_PSTATE
6 bool "Intel P state control"
7 depends on X86
8 help
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.
16 If in doubt, say N.
18 config X86_PCC_CPUFREQ
19 tristate "Processor Clocking Control interface driver"
20 depends on ACPI && ACPI_PROCESSOR
21 help
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.
30 If in doubt, say N.
32 config X86_ACPI_CPUFREQ
33 tristate "ACPI Processor P-States driver"
34 select CPU_FREQ_TABLE
35 depends on ACPI_PROCESSOR
36 help
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
40 AMD CPUs.
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/>.
47 If in doubt, say N.
49 config X86_ACPI_CPUFREQ_CPB
50 default y
51 bool "Legacy cpb sysfs knob support for AMD CPUs"
52 depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD
53 help
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.
61 config ELAN_CPUFREQ
62 tristate "AMD Elan SC400 and SC410"
63 select CPU_FREQ_TABLE
64 depends on MELAN
65 ---help---
66 This adds the CPUFreq driver for AMD Elan SC400 and SC410
67 processors.
69 You need to specify the processor maximum speed as boot
70 parameter: elanfreq=maxspeed (in kHz) or as module
71 parameter "max_freq".
73 For details, take a look at <file:Documentation/cpu-freq/>.
75 If in doubt, say N.
77 config SC520_CPUFREQ
78 tristate "AMD Elan SC520"
79 select CPU_FREQ_TABLE
80 depends on MELAN
81 ---help---
82 This adds the CPUFreq driver for AMD Elan SC520 processor.
84 For details, take a look at <file:Documentation/cpu-freq/>.
86 If in doubt, say N.
89 config X86_POWERNOW_K6
90 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
91 select CPU_FREQ_TABLE
92 depends on X86_32
93 help
94 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
95 AMD K6-3+ processors.
97 For details, take a look at <file:Documentation/cpu-freq/>.
99 If in doubt, say N.
101 config X86_POWERNOW_K7
102 tristate "AMD Mobile Athlon/Duron PowerNow!"
103 select CPU_FREQ_TABLE
104 depends on X86_32
105 help
106 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
108 For details, take a look at <file:Documentation/cpu-freq/>.
110 If in doubt, say N.
112 config X86_POWERNOW_K7_ACPI
113 bool
114 depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
115 depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
116 depends on X86_32
117 default y
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
123 help
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
135 select CPU_FREQ_TABLE
136 help
137 This adds AMD-specific powersave bias function to the ondemand
138 governor, which allows it to make more power-conscious frequency
139 change decisions based on feedback from hardware (availble on AMD
140 Family 16h and above).
142 Hardware feedback tells software how "sensitive" to frequency changes
143 the CPUs' workloads are. CPU-bound workloads will be more sensitive
144 -- they will perform better as frequency increases. Memory/IO-bound
145 workloads will be less sensitive -- they will not necessarily perform
146 better as frequency increases.
148 If in doubt, say N.
150 config X86_GX_SUSPMOD
151 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
152 depends on X86_32 && PCI
153 help
154 This add the CPUFreq driver for NatSemi Geode processors which
155 support suspend modulation.
157 For details, take a look at <file:Documentation/cpu-freq/>.
159 If in doubt, say N.
161 config X86_SPEEDSTEP_CENTRINO
162 tristate "Intel Enhanced SpeedStep (deprecated)"
163 select CPU_FREQ_TABLE
164 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
165 depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
166 help
167 This is deprecated and this functionality is now merged into
168 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
169 speedstep_centrino.
170 This adds the CPUFreq driver for Enhanced SpeedStep enabled
171 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
172 or 64bit enabled Intel Xeons.
174 To compile this driver as a module, choose M here: the
175 module will be called speedstep-centrino.
177 For details, take a look at <file:Documentation/cpu-freq/>.
179 If in doubt, say N.
181 config X86_SPEEDSTEP_CENTRINO_TABLE
182 bool "Built-in tables for Banias CPUs"
183 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
184 default y
185 help
186 Use built-in tables for Banias CPUs if ACPI encoding
187 is not available.
189 If in doubt, say N.
191 config X86_SPEEDSTEP_ICH
192 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
193 select CPU_FREQ_TABLE
194 depends on X86_32
195 help
196 This adds the CPUFreq driver for certain mobile Intel Pentium III
197 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
198 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
199 ICH3 or ICH4 southbridge.
201 For details, take a look at <file:Documentation/cpu-freq/>.
203 If in doubt, say N.
205 config X86_SPEEDSTEP_SMI
206 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
207 select CPU_FREQ_TABLE
208 depends on X86_32
209 help
210 This adds the CPUFreq driver for certain mobile Intel Pentium III
211 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
212 on systems which have an Intel 440BX/ZX/MX southbridge.
214 For details, take a look at <file:Documentation/cpu-freq/>.
216 If in doubt, say N.
218 config X86_P4_CLOCKMOD
219 tristate "Intel Pentium 4 clock modulation"
220 select CPU_FREQ_TABLE
221 help
222 This adds the CPUFreq driver for Intel Pentium 4 / XEON
223 processors. When enabled it will lower CPU temperature by skipping
224 clocks.
226 This driver should be only used in exceptional
227 circumstances when very low power is needed because it causes severe
228 slowdowns and noticeable latencies. Normally Speedstep should be used
229 instead.
231 To compile this driver as a module, choose M here: the
232 module will be called p4-clockmod.
234 For details, take a look at <file:Documentation/cpu-freq/>.
236 Unless you are absolutely sure say N.
238 config X86_CPUFREQ_NFORCE2
239 tristate "nVidia nForce2 FSB changing"
240 depends on X86_32
241 help
242 This adds the CPUFreq driver for FSB changing on nVidia nForce2
243 platforms.
245 For details, take a look at <file:Documentation/cpu-freq/>.
247 If in doubt, say N.
249 config X86_LONGRUN
250 tristate "Transmeta LongRun"
251 depends on X86_32
252 help
253 This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
254 which support LongRun.
256 For details, take a look at <file:Documentation/cpu-freq/>.
258 If in doubt, say N.
260 config X86_LONGHAUL
261 tristate "VIA Cyrix III Longhaul"
262 select CPU_FREQ_TABLE
263 depends on X86_32 && ACPI_PROCESSOR
264 help
265 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
266 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
267 processors.
269 For details, take a look at <file:Documentation/cpu-freq/>.
271 If in doubt, say N.
273 config X86_E_POWERSAVER
274 tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)"
275 select CPU_FREQ_TABLE
276 depends on X86_32 && ACPI_PROCESSOR
277 help
278 This adds the CPUFreq driver for VIA C7 processors. However, this driver
279 does not have any safeguards to prevent operating the CPU out of spec
280 and is thus considered dangerous. Please use the regular ACPI cpufreq
281 driver, enabled by CONFIG_X86_ACPI_CPUFREQ.
283 If in doubt, say N.
285 comment "shared options"
287 config X86_SPEEDSTEP_LIB
288 tristate
289 default (X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD)
291 config X86_SPEEDSTEP_RELAXED_CAP_CHECK
292 bool "Relaxed speedstep capability checks"
293 depends on X86_32 && (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH)
294 help
295 Don't perform all checks for a speedstep capable system which would
296 normally be done. Some ancient or strange systems, though speedstep
297 capable, don't always indicate that they are speedstep capable. This
298 option lets the probing code bypass some of those checks if the
299 parameter "relaxed_check=1" is passed to the module.