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config CPU_FREQ
bool "CPU Frequency scaling"
help
CPU Frequency scaling allows you to change the clock speed of
CPUs on the fly. This is a nice method to save power, because
the lower the CPU clock speed, the less power the CPU consumes.
Note that this driver doesn't automatically change the CPU
clock speed, you need to either enable a dynamic cpufreq governor
(see below) after boot, or use a userspace tool.
For details, take a look at <file:Documentation/cpu-freq>.
If in doubt, say N.
config CPU_FREQ_DEBUG
bool "Enable CPUfreq debugging"
depends on CPU_FREQ
help
Say Y here to enable CPUfreq subsystem (including drivers)
debugging. You will need to activate it via the kernel
command line by passing
cpufreq.debug=<value>
To get <value>, add
1 to activate CPUfreq core debugging,
2 to activate CPUfreq drivers debugging, and
4 to activate CPUfreq governor debugging
config CPU_FREQ_STAT
tristate "CPU frequency translation statistics"
depends on CPU_FREQ && CPU_FREQ_TABLE
default y
help
This driver exports CPU frequency statistics information through sysfs
file system
config CPU_FREQ_STAT_DETAILS
bool "CPU frequency translation statistics details"
depends on CPU_FREQ && CPU_FREQ_STAT
default n
help
This will show detail CPU frequency translation table in sysfs file
system
choice
prompt "Default CPUFreq governor"
depends on CPU_FREQ
default CPU_FREQ_DEFAULT_GOV_PERFORMANCE if !CPU_FREQ_SA1100 && !CPU_FREQ_SA1110
default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110
help
This option sets which CPUFreq governor shall be loaded at
startup. If in doubt, select 'performance'.
config CPU_FREQ_DEFAULT_GOV_PERFORMANCE
bool "performance"
select CPU_FREQ_GOV_PERFORMANCE
help
Use the CPUFreq governor 'performance' as default. This sets
the frequency statically to the highest frequency supported by
the CPU.
config CPU_FREQ_DEFAULT_GOV_USERSPACE
bool "userspace"
select CPU_FREQ_GOV_USERSPACE
help
Use the CPUFreq governor 'userspace' as default. This allows
you to set the CPU frequency manually or when an userspace
program shall be able to set the CPU dynamically without having
to enable the userspace governor manually.
endchoice
config CPU_FREQ_GOV_PERFORMANCE
tristate "'performance' governor"
depends on CPU_FREQ
help
This cpufreq governor sets the frequency statically to the
highest available CPU frequency.
If in doubt, say Y.
config CPU_FREQ_GOV_POWERSAVE
tristate "'powersave' governor"
depends on CPU_FREQ
help
This cpufreq governor sets the frequency statically to the
lowest available CPU frequency.
If in doubt, say Y.
config CPU_FREQ_GOV_USERSPACE
tristate "'userspace' governor for userspace frequency scaling"
depends on CPU_FREQ
help
Enable this cpufreq governor when you either want to set the
CPU frequency manually or when an userspace program shall
be able to set the CPU dynamically, like on LART
<http://www.lart.tudelft.nl/>
For details, take a look at <file:Documentation/cpu-freq/>.
If in doubt, say Y.
config CPU_FREQ_GOV_ONDEMAND
tristate "'ondemand' cpufreq policy governor"
depends on CPU_FREQ
help
'ondemand' - This driver adds a dynamic cpufreq policy governor.
The governor does a periodic polling and
changes frequency based on the CPU utilization.
The support for this governor depends on CPU capability to
do fast frequency switching (i.e, very low latency frequency
transitions).
For details, take a look at linux/Documentation/cpu-freq.
If in doubt, say N.