2 # x86 CPU Frequency scaling drivers
6 tristate
"Processor Clocking Control interface driver"
7 depends on ACPI
&& ACPI_PROCESSOR
9 This driver adds support for the PCC interface.
11 For details
, take a look
at:
12 <file:Documentation
/cpu
-freq
/pcc
-cpufreq.txt
>.
14 To compile
this driver as a module
, choose M
here: the
15 module will be called pcc
-cpufreq.
19 config X86_ACPI_CPUFREQ
20 tristate
"ACPI Processor P-States driver"
22 depends on ACPI_PROCESSOR
24 This driver adds a CPUFreq driver which utilizes the ACPI
25 Processor Performance States.
26 This driver also supports Intel Enhanced Speedstep.
28 To compile
this driver as a module
, choose M
here: the
29 module will be called acpi
-cpufreq.
31 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
36 tristate
"AMD Elan SC400 and SC410"
40 This adds the CPUFreq driver for AMD Elan SC400
and SC410
43 You need to specify the processor maximum speed as boot
44 parameter: elanfreq
=maxspeed
(in kHz
) or as module
47 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
52 tristate
"AMD Elan SC520"
56 This adds the CPUFreq driver for AMD Elan SC520 processor.
58 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
63 config X86_POWERNOW_K6
64 tristate
"AMD Mobile K6-2/K6-3 PowerNow!"
68 This adds the CPUFreq driver for mobile AMD K6
-2+ and mobile
71 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
75 config X86_POWERNOW_K7
76 tristate
"AMD Mobile Athlon/Duron PowerNow!"
80 This adds the CPUFreq driver for mobile AMD K7 mobile processors.
82 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
86 config X86_POWERNOW_K7_ACPI
88 depends on X86_POWERNOW_K7
&& ACPI_PROCESSOR
89 depends on
!(X86_POWERNOW_K7
= y
&& ACPI_PROCESSOR
= m
)
93 config X86_POWERNOW_K8
94 tristate
"AMD Opteron/Athlon64 PowerNow!"
96 depends on ACPI
&& ACPI_PROCESSOR
98 This adds the CPUFreq driver for K8
/K10 Opteron
/Athlon64 processors.
100 To compile
this driver as a module
, choose M
here: the
101 module will be called powernow
-k8.
103 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
105 config X86_GX_SUSPMOD
106 tristate
"Cyrix MediaGX/NatSemi Geode Suspend Modulation"
107 depends on X86_32
&& PCI
109 This add the CPUFreq driver for NatSemi Geode processors which
110 support suspend modulation.
112 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
116 config X86_SPEEDSTEP_CENTRINO
117 tristate
"Intel Enhanced SpeedStep (deprecated)"
118 select CPU_FREQ_TABLE
119 select X86_SPEEDSTEP_CENTRINO_TABLE if X86_32
120 depends on X86_32 ||
(X86_64
&& ACPI_PROCESSOR
)
122 This is deprecated
and this functionality is now merged
into
123 acpi_cpufreq
(X86_ACPI_CPUFREQ
). Use that driver instead of
125 This adds the CPUFreq driver for Enhanced SpeedStep enabled
126 mobile CPUs.
This means Intel Pentium M
(Centrino
) CPUs
127 or 64bit enabled Intel Xeons.
129 To compile
this driver as a module
, choose M
here: the
130 module will be called speedstep
-centrino.
132 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
136 config X86_SPEEDSTEP_CENTRINO_TABLE
137 bool
"Built-in tables for Banias CPUs"
138 depends on X86_32
&& X86_SPEEDSTEP_CENTRINO
141 Use built
-in tables for Banias CPUs if ACPI encoding
146 config X86_SPEEDSTEP_ICH
147 tristate
"Intel Speedstep on ICH-M chipsets (ioport interface)"
148 select CPU_FREQ_TABLE
151 This adds the CPUFreq driver for certain mobile Intel Pentium III
152 (Coppermine
), all mobile Intel Pentium III
-M
(Tualatin
) and all
153 mobile Intel Pentium
4 P4
-M on systems which have an Intel ICH2
,
154 ICH3
or ICH4 southbridge.
156 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
160 config X86_SPEEDSTEP_SMI
161 tristate
"Intel SpeedStep on 440BX/ZX/MX chipsets (SMI interface)"
162 select CPU_FREQ_TABLE
163 depends on X86_32
&& EXPERIMENTAL
165 This adds the CPUFreq driver for certain mobile Intel Pentium III
166 (Coppermine
), all mobile Intel Pentium III
-M
(Tualatin
)
167 on systems which have an Intel
440BX
/ZX
/MX southbridge.
169 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
173 config X86_P4_CLOCKMOD
174 tristate
"Intel Pentium 4 clock modulation"
175 select CPU_FREQ_TABLE
177 This adds the CPUFreq driver for Intel Pentium
4 / XEON
178 processors. When enabled it will lower CPU temperature by skipping
181 This driver should be only used
in exceptional
182 circumstances when very
low power is needed because it causes severe
183 slowdowns
and noticeable latencies. Normally Speedstep should be used
186 To compile
this driver as a module
, choose M
here: the
187 module will be called p4
-clockmod.
189 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
191 Unless you are absolutely sure say N.
193 config X86_CPUFREQ_NFORCE2
194 tristate
"nVidia nForce2 FSB changing"
195 depends on X86_32
&& EXPERIMENTAL
197 This adds the CPUFreq driver for FSB changing on nVidia nForce2
200 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
205 tristate
"Transmeta LongRun"
208 This adds the CPUFreq driver for Transmeta Crusoe
and Efficeon processors
209 which support LongRun.
211 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
216 tristate
"VIA Cyrix III Longhaul"
217 select CPU_FREQ_TABLE
218 depends on X86_32
&& ACPI_PROCESSOR
220 This adds the CPUFreq driver for VIA Samuel
/CyrixIII
,
221 VIA Cyrix Samuel
/C3
, VIA Cyrix Ezra
and VIA Cyrix Ezra
-T
224 For details
, take a look at
<file:Documentation
/cpu
-freq
/>.
228 config X86_E_POWERSAVER
229 tristate
"VIA C7 Enhanced PowerSaver (DANGEROUS)"
230 select CPU_FREQ_TABLE
231 depends on X86_32
&& EXPERIMENTAL
233 This adds the CPUFreq driver for VIA C7 processors. However
, this driver
234 does
not have any safeguards to prevent operating the CPU
out of spec
235 and is thus considered dangerous. Please use the regular ACPI cpufreq
236 driver
, enabled by CONFIG_X86_ACPI_CPUFREQ.
240 comment
"shared options"
242 config X86_SPEEDSTEP_LIB
244 default
(X86_SPEEDSTEP_ICH || X86_SPEEDSTEP_SMI || X86_P4_CLOCKMOD
)
246 config X86_SPEEDSTEP_RELAXED_CAP_CHECK
247 bool
"Relaxed speedstep capability checks"
248 depends on X86_32
&& (X86_SPEEDSTEP_SMI || X86_SPEEDSTEP_ICH
)
250 Don
't perform all checks for a speedstep capable system which would
251 normally be done. Some ancient or strange systems, though speedstep
252 capable, don't always indicate that they are speedstep capable.
This
253 option lets the probing code bypass some of those checks if the
254 parameter
"relaxed_check=1" is passed to the module.