docs: fix Co-Developed-by docs
[linux/fpc-iii.git] / drivers / cpufreq / Kconfig.x86
blob35f71825b7f3020980555612bdf13db7d095aef4
2 # x86 CPU Frequency scaling drivers
5 config X86_INTEL_PSTATE
6 bool "Intel P state control"
7 depends on X86
8 select ACPI_PROCESSOR if ACPI
9 select ACPI_CPPC_LIB if X86_64 && ACPI && SCHED_MC_PRIO
10 help
11 This driver provides a P state for Intel core processors.
12 The driver implements an internal governor and will become
13 the scaling driver and governor for Sandy bridge processors.
15 When this driver is enabled it will become the preferred
16 scaling driver for Sandy bridge processors.
18 If in doubt, say N.
20 config X86_PCC_CPUFREQ
21 tristate "Processor Clocking Control interface driver"
22 depends on ACPI && ACPI_PROCESSOR
23 help
24 This driver adds support for the PCC interface.
26 For details, take a look at:
27 <file:Documentation/cpu-freq/pcc-cpufreq.txt>.
29 To compile this driver as a module, choose M here: the
30 module will be called pcc-cpufreq.
32 If in doubt, say N.
34 config X86_ACPI_CPUFREQ
35 tristate "ACPI Processor P-States driver"
36 depends on ACPI_PROCESSOR
37 help
38 This driver adds a CPUFreq driver which utilizes the ACPI
39 Processor Performance States.
40 This driver also supports Intel Enhanced Speedstep and newer
41 AMD CPUs.
43 To compile this driver as a module, choose M here: the
44 module will be called acpi-cpufreq.
46 For details, take a look at <file:Documentation/cpu-freq/>.
48 If in doubt, say N.
50 config X86_ACPI_CPUFREQ_CPB
51 default y
52 bool "Legacy cpb sysfs knob support for AMD CPUs"
53 depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD
54 help
55 The powernow-k8 driver used to provide a sysfs knob called "cpb"
56 to disable the Core Performance Boosting feature of AMD CPUs. This
57 file has now been superseded by the more generic "boost" entry.
59 By enabling this option the acpi_cpufreq driver provides the old
60 entry in addition to the new boost ones, for compatibility reasons.
62 config X86_SFI_CPUFREQ
63 tristate "SFI Performance-States driver"
64 depends on X86_INTEL_MID && SFI
65 help
66 This adds a CPUFreq driver for some Silvermont based Intel Atom
67 architectures like Z34xx and Z35xx which enumerate processor
68 performance states through SFI.
70 If in doubt, say N.
72 config ELAN_CPUFREQ
73 tristate "AMD Elan SC400 and SC410"
74 depends on MELAN
75 ---help---
76 This adds the CPUFreq driver for AMD Elan SC400 and SC410
77 processors.
79 You need to specify the processor maximum speed as boot
80 parameter: elanfreq=maxspeed (in kHz) or as module
81 parameter "max_freq".
83 For details, take a look at <file:Documentation/cpu-freq/>.
85 If in doubt, say N.
87 config SC520_CPUFREQ
88 tristate "AMD Elan SC520"
89 depends on MELAN
90 ---help---
91 This adds the CPUFreq driver for AMD Elan SC520 processor.
93 For details, take a look at <file:Documentation/cpu-freq/>.
95 If in doubt, say N.
98 config X86_POWERNOW_K6
99 tristate "AMD Mobile K6-2/K6-3 PowerNow!"
100 depends on X86_32
101 help
102 This adds the CPUFreq driver for mobile AMD K6-2+ and mobile
103 AMD K6-3+ processors.
105 For details, take a look at <file:Documentation/cpu-freq/>.
107 If in doubt, say N.
109 config X86_POWERNOW_K7
110 tristate "AMD Mobile Athlon/Duron PowerNow!"
111 depends on X86_32
112 help
113 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
115 For details, take a look at <file:Documentation/cpu-freq/>.
117 If in doubt, say N.
119 config X86_POWERNOW_K7_ACPI
120 bool
121 depends on X86_POWERNOW_K7 && ACPI_PROCESSOR
122 depends on !(X86_POWERNOW_K7 = y && ACPI_PROCESSOR = m)
123 depends on X86_32
124 default y
126 config X86_POWERNOW_K8
127 tristate "AMD Opteron/Athlon64 PowerNow!"
128 depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
129 help
130 This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
131 Support for K10 and newer processors is now in acpi-cpufreq.
133 To compile this driver as a module, choose M here: the
134 module will be called powernow-k8.
136 For details, take a look at <file:Documentation/cpu-freq/>.
138 config X86_AMD_FREQ_SENSITIVITY
139 tristate "AMD frequency sensitivity feedback powersave bias"
140 depends on CPU_FREQ_GOV_ONDEMAND && X86_ACPI_CPUFREQ && CPU_SUP_AMD
141 help
142 This adds AMD-specific powersave bias function to the ondemand
143 governor, which allows it to make more power-conscious frequency
144 change decisions based on feedback from hardware (available on AMD
145 Family 16h and above).
147 Hardware feedback tells software how "sensitive" to frequency changes
148 the CPUs' workloads are. CPU-bound workloads will be more sensitive
149 -- they will perform better as frequency increases. Memory/IO-bound
150 workloads will be less sensitive -- they will not necessarily perform
151 better as frequency increases.
153 If in doubt, say N.
155 config X86_GX_SUSPMOD
156 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
157 depends on X86_32 && PCI
158 help
159 This add the CPUFreq driver for NatSemi Geode processors which
160 support suspend modulation.
162 For details, take a look at <file:Documentation/cpu-freq/>.
164 If in doubt, say N.
166 config X86_SPEEDSTEP_CENTRINO
167 tristate "Intel Enhanced SpeedStep (deprecated)"
168 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
169 depends on X86_32 || (X86_64 && ACPI_PROCESSOR)
170 help
171 This is deprecated and this functionality is now merged into
172 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
173 speedstep_centrino.
174 This adds the CPUFreq driver for Enhanced SpeedStep enabled
175 mobile CPUs. This means Intel Pentium M (Centrino) CPUs
176 or 64bit enabled Intel Xeons.
178 To compile this driver as a module, choose M here: the
179 module will be called speedstep-centrino.
181 For details, take a look at <file:Documentation/cpu-freq/>.
183 If in doubt, say N.
185 config X86_SPEEDSTEP_CENTRINO_TABLE
186 bool "Built-in tables for Banias CPUs"
187 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
188 default y
189 help
190 Use built-in tables for Banias CPUs if ACPI encoding
191 is not available.
193 If in doubt, say N.
195 config X86_SPEEDSTEP_ICH
196 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
197 depends on X86_32
198 help
199 This adds the CPUFreq driver for certain mobile Intel Pentium III
200 (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all
201 mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2,
202 ICH3 or ICH4 southbridge.
204 For details, take a look at <file:Documentation/cpu-freq/>.
206 If in doubt, say N.
208 config X86_SPEEDSTEP_SMI
209 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
210 depends on X86_32
211 help
212 This adds the CPUFreq driver for certain mobile Intel Pentium III
213 (Coppermine), all mobile Intel Pentium III-M (Tualatin)
214 on systems which have an Intel 440BX/ZX/MX southbridge.
216 For details, take a look at <file:Documentation/cpu-freq/>.
218 If in doubt, say N.
220 config X86_P4_CLOCKMOD
221 tristate "Intel Pentium 4 clock modulation"
222 help
223 This adds the CPUFreq driver for Intel Pentium 4 / XEON
224 processors. When enabled it will lower CPU temperature by skipping
225 clocks.
227 This driver should be only used in exceptional
228 circumstances when very low power is needed because it causes severe
229 slowdowns and noticeable latencies. Normally Speedstep should be used
230 instead.
232 To compile this driver as a module, choose M here: the
233 module will be called p4-clockmod.
235 For details, take a look at <file:Documentation/cpu-freq/>.
237 Unless you are absolutely sure say N.
239 config X86_CPUFREQ_NFORCE2
240 tristate "nVidia nForce2 FSB changing"
241 depends on X86_32
242 help
243 This adds the CPUFreq driver for FSB changing on nVidia nForce2
244 platforms.
246 For details, take a look at <file:Documentation/cpu-freq/>.
248 If in doubt, say N.
250 config X86_LONGRUN
251 tristate "Transmeta LongRun"
252 depends on X86_32
253 help
254 This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors
255 which support LongRun.
257 For details, take a look at <file:Documentation/cpu-freq/>.
259 If in doubt, say N.
261 config X86_LONGHAUL
262 tristate "VIA Cyrix III Longhaul"
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 depends on X86_32 && ACPI_PROCESSOR
276 help
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.
282 If in doubt, say N.
284 comment "shared options"
286 config X86_SPEEDSTEP_LIB
287 tristate
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)
293 help
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.