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
135 select CPU_FREQ_TABLE
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.
150 config X86_GX_SUSPMOD
151 tristate "Cyrix MediaGX/NatSemi Geode Suspend Modulation"
152 depends on X86_32 && PCI
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/>.
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)
167 This is deprecated and this functionality is now merged into
168 acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
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/>.
181 config X86_SPEEDSTEP_CENTRINO_TABLE
182 bool "Built-in tables for Banias CPUs"
183 depends on X86_32 && X86_SPEEDSTEP_CENTRINO
186 Use built-in tables for Banias CPUs if ACPI encoding
191 config X86_SPEEDSTEP_ICH
192 tristate "Intel Speedstep on ICH-M chipsets (ioport interface)"
193 select CPU_FREQ_TABLE
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/>.
205 config X86_SPEEDSTEP_SMI
206 tristate "Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
207 select CPU_FREQ_TABLE
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/>.
218 config X86_P4_CLOCKMOD
219 tristate "Intel Pentium 4 clock modulation"
220 select CPU_FREQ_TABLE
222 This adds the CPUFreq driver for Intel Pentium 4 / XEON
223 processors. When enabled it will lower CPU temperature by skipping
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
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"
242 This adds the CPUFreq driver for FSB changing on nVidia nForce2
245 For details, take a look at <file:Documentation/cpu-freq/>.
250 tristate "Transmeta LongRun"
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/>.
261 tristate "VIA Cyrix III Longhaul"
262 select CPU_FREQ_TABLE
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 select CPU_FREQ_TABLE
276 depends on X86_32 && ACPI_PROCESSOR
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.
285 comment "shared options"
287 config X86_SPEEDSTEP_LIB
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)
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.