2 # x86 CPU Frequency scaling drivers
5 config X86_INTEL_PSTATE
6 bool
"Intel P state control"
8 select ACPI_PROCESSOR if ACPI
9 select ACPI_CPPC_LIB if X86_64
&& ACPI
&& SCHED_MC_PRIO
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.
20 config X86_PCC_CPUFREQ
21 tristate
"Processor Clocking Control interface driver"
22 depends on ACPI
&& ACPI_PROCESSOR
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.
34 config X86_ACPI_CPUFREQ
35 tristate
"ACPI Processor P-States driver"
36 depends on ACPI_PROCESSOR
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
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
/>.
50 config X86_ACPI_CPUFREQ_CPB
52 bool
"Legacy cpb sysfs knob support for AMD CPUs"
53 depends on X86_ACPI_CPUFREQ
&& CPU_SUP_AMD
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57 file has now been superseded by the more generic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
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.
73 tristate
"AMD Elan SC400 and SC410"
76 This adds the CPUFreq driver for AMD Elan SC400
and SC410
79 You need to specify the processor maximum speed as boot
80 parameter: elanfreq
=maxspeed
(in kHz
) or as module
83 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
88 tristate
"AMD Elan SC520"
91 This adds the CPUFreq driver for AMD Elan SC520 processor.
93 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
98 config X86_POWERNOW_K6
99 tristate
"AMD Mobile K6-2/K6-3 PowerNow!"
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
/>.
109 config X86_POWERNOW_K7
110 tristate
"AMD Mobile Athlon/Duron PowerNow!"
113 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
115 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
119 config X86_POWERNOW_K7_ACPI
121 depends on X86_POWERNOW_K7
&& ACPI_PROCESSOR
122 depends on
!(X86_POWERNOW_K7
= y
&& ACPI_PROCESSOR
= m
)
126 config X86_POWERNOW_K8
127 tristate
"AMD Opteron/Athlon64 PowerNow!"
128 depends on ACPI
&& ACPI_PROCESSOR
&& X86_ACPI_CPUFREQ
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
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.
155 config X86_GX_SUSPMOD
156 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
157 depends on X86_32 && PCI
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/>.
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)
171 This is deprecated and this functionality is now merged into
172 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
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/>.
185 config X86_SPEEDSTEP_CENTRINO_TABLE
186 bool "Built-in tables for Banias CPUs"
187 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
190 Use built-in tables for Banias CPUs if ACPI encoding
195 config X86_SPEEDSTEP_ICH
196 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
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/>.
208 config X86_SPEEDSTEP_SMI
209 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
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/>.
220 config X86_P4_CLOCKMOD
221 tristate "Intel Pentium 4 clock modulation"
223 This adds the CPUFreq driver for Intel Pentium 4 / XEON
224 processors. When enabled it will lower CPU temperature by skipping
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
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"
243 This adds the CPUFreq driver for FSB changing on nVidia nForce2
246 For details, take a look at <file:Documentation/cpu-freq/>.
251 tristate "Transmeta LongRun"
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/>.
262 tristate "VIA Cyrix III Longhaul"
263 depends on X86_32 && ACPI_PROCESSOR
265 This adds the CPUFreq driver for VIA Samuel/CyrixIII,
266 VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T
269 For details, take a look at <file:Documentation/cpu-freq/>.
273 config X86_E_POWERSAVER
274 tristate "VIA C7 Enhanced PowerSaver (DANGEROUS)"
275 depends on X86_32 && ACPI_PROCESSOR
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.