menu "CPU Frequency scaling"
-config CPU_FREQ
- bool "CPU Frequency scaling"
- help
- Clock scaling allows you to change the clock speed of CPUs on the
- fly. This is a nice method to save battery power on notebooks,
- because the lower the clock speed, the less power the CPU consumes.
-
- For more information, take a look at <file:Documentation/cpu-freq/>
- or at <http://www.codemonkey.org.uk/projects/cpufreq/>
-
- If in doubt, say N.
-
source "drivers/cpufreq/Kconfig"
-config CPU_FREQ_TABLE
- tristate "CPU frequency table helpers"
- depends on CPU_FREQ
- default y
- help
- Many CPUFreq drivers use these helpers, so only say N here if
- the CPUFreq driver of your choice doesn't need these helpers.
-
- If in doubt, say Y.
+if CPU_FREQ
comment "CPUFreq processor drivers"
- depends on CPU_FREQ
config X86_POWERNOW_K8
tristate "AMD Opteron/Athlon64 PowerNow!"
- depends on CPU_FREQ_TABLE
+ select CPU_FREQ_TABLE
help
This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors.
config X86_POWERNOW_K8_ACPI
bool
- depends on ((X86_POWERNOW_K8 = "m" && ACPI_PROCESSOR) || (X86_POWERNOW_K8 = "y" && ACPI_PROCESSOR = "y"))
+ depends on X86_POWERNOW_K8 && ACPI_PROCESSOR
+ depends on !(X86_POWERNOW_K8 = y && ACPI_PROCESSOR = m)
default y
config X86_SPEEDSTEP_CENTRINO
- tristate "Intel Enhanced SpeedStep"
- depends on CPU_FREQ_TABLE
+ tristate "Intel Enhanced SpeedStep (deprecated)"
+ select CPU_FREQ_TABLE
+ depends on ACPI_PROCESSOR
help
+ This is deprecated and this functionality is now merged into
+ acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of
+ speedstep_centrino.
This adds the CPUFreq driver for Enhanced SpeedStep enabled
mobile CPUs. This means Intel Pentium M (Centrino) CPUs
or 64bit enabled Intel Xeons.
If in doubt, say N.
-config X86_SPEEDSTEP_CENTRINO_TABLE
+config X86_SPEEDSTEP_CENTRINO_ACPI
bool
depends on X86_SPEEDSTEP_CENTRINO
default y
-config X86_SPEEDSTEP_CENTRINO_ACPI
- bool "Use ACPI tables to decode valid frequency/voltage pairs (EXPERIMENTAL)"
- depends on EXPERIMENTAL
- depends on ((X86_SPEEDSTEP_CENTRINO = "m" && ACPI_PROCESSOR) || (X86_SPEEDSTEP_CENTRINO = "y" && ACPI_PROCESSOR = "y"))
- help
- Use primarily the information provided in the BIOS ACPI tables
- to determine valid CPU frequency and voltage pairings.
-
- If in doubt, say Y.
-
config X86_ACPI_CPUFREQ
tristate "ACPI Processor P-States driver"
- depends on CPU_FREQ_TABLE && ACPI_PROCESSOR
+ select CPU_FREQ_TABLE
+ depends on ACPI_PROCESSOR
help
This driver adds a CPUFreq driver which utilizes the ACPI
Processor Performance States.
+ This driver also supports Intel Enhanced Speedstep.
For details, take a look at <file:Documentation/cpu-freq/>.
If in doubt, say N.
+comment "shared options"
+
config X86_ACPI_CPUFREQ_PROC_INTF
bool "/proc/acpi/processor/../performance interface (deprecated)"
- depends on X86_ACPI_CPUFREQ && PROC_FS
+ depends on PROC_FS
+ depends on X86_ACPI_CPUFREQ || X86_SPEEDSTEP_CENTRINO_ACPI || X86_POWERNOW_K8_ACPI
help
This enables the deprecated /proc/acpi/processor/../performance
interface. While it is helpful for debugging, the generic,
If in doubt, say N.
+config X86_P4_CLOCKMOD
+ tristate "Intel Pentium 4 clock modulation"
+ depends on EMBEDDED
+ help
+ This adds the clock modulation driver for Intel Pentium 4 / XEON
+ processors. When enabled it will lower CPU temperature by skipping
+ clocks.
+
+ This driver should be only used in exceptional
+ circumstances when very low power is needed because it causes severe
+ slowdowns and noticeable latencies. Normally Speedstep should be used
+ instead.
+
+ For details, take a look at <file:Documentation/cpu-freq/>.
+
+ Unless you are absolutely sure say N.
+
+
+config X86_SPEEDSTEP_LIB
+ tristate
+ default X86_P4_CLOCKMOD
+
+endif
+
endmenu