Merge branch 'pm-cpufreq' (885f925e) · Commits · 戴 / test

Documentation/cpu-freq/cpu-drivers.txt

+5 −4

Original line number	Diff line number	Diff line
		@@ -108,8 +108,9 @@ policy->governor must contain the "default policy" for
		cpufreq_driver.target is called with
		these values.

		For setting some of these values, the frequency table helpers might be
		helpful. See the section 2 for more information on them.
		For setting some of these values (cpuinfo.min[max]_freq, policy->min[max]), the
		frequency table helpers might be helpful. See the section 2 for more information
		on them.

		SMP systems normally have same clock source for a group of cpus. For these the
		.init() would be called only once for the first online cpu. Here the .init()
		@@ -184,10 +185,10 @@ the reference implementation in drivers/cpufreq/longrun.c
		As most cpufreq processors only allow for being set to a few specific
		frequencies, a "frequency table" with some functions might assist in
		some work of the processor driver. Such a "frequency table" consists
		of an array of struct cpufreq_freq_table entries, with any value in
		of an array of struct cpufreq_frequency_table entries, with any value in
		"index" you want to use, and the corresponding frequency in
		"frequency". At the end of the table, you need to add a
		cpufreq_freq_table entry with frequency set to CPUFREQ_TABLE_END. And
		cpufreq_frequency_table entry with frequency set to CPUFREQ_TABLE_END. And
		if you want to skip one entry in the table, set the frequency to
		CPUFREQ_ENTRY_INVALID. The entries don't need to be in ascending
		order.

Documentation/cpu-freq/governors.txt

+27 −0

Original line number	Diff line number	Diff line
		@@ -167,6 +167,27 @@ of load evaluation and helping the CPU stay at its top speed when truly
		busy, rather than shifting back and forth in speed. This tunable has no
		effect on behavior at lower speeds/lower CPU loads.

		powersave_bias: this parameter takes a value between 0 to 1000. It
		defines the percentage (times 10) value of the target frequency that
		will be shaved off of the target. For example, when set to 100 -- 10%,
		when ondemand governor would have targeted 1000 MHz, it will target
		1000 MHz - (10% of 1000 MHz) = 900 MHz instead. This is set to 0
		(disabled) by default.
		When AMD frequency sensitivity powersave bias driver --
		drivers/cpufreq/amd_freq_sensitivity.c is loaded, this parameter
		defines the workload frequency sensitivity threshold in which a lower
		frequency is chosen instead of ondemand governor's original target.
		The frequency sensitivity is a hardware reported (on AMD Family 16h
		Processors and above) value between 0 to 100% that tells software how
		the performance of the workload running on a CPU will change when
		frequency changes. A workload with sensitivity of 0% (memory/IO-bound)
		will not perform any better on higher core frequency, whereas a
		workload with sensitivity of 100% (CPU-bound) will perform better
		higher the frequency. When the driver is loaded, this is set to 400
		by default -- for CPUs running workloads with sensitivity value below
		40%, a lower frequency is chosen. Unloading the driver or writing 0
		will disable this feature.


		2.5 Conservative
		----------------
		@@ -191,6 +212,12 @@ governor but for the opposite direction. For example when set to its
		default value of '20' it means that if the CPU usage needs to be below
		20% between samples to have the frequency decreased.

		sampling_down_factor: similar functionality as in "ondemand" governor.
		But in "conservative", it controls the rate at which the kernel makes
		a decision on when to decrease the frequency while running in any
		speed. Load for frequency increase is still evaluated every
		sampling rate.

		3. The Governor Interface in the CPUfreq Core
		=============================================

Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt

0 → 100644

+65 −0

Original line number	Diff line number	Diff line
		Generic ARM big LITTLE cpufreq driver's DT glue
		-----------------------------------------------

		This is DT specific glue layer for generic cpufreq driver for big LITTLE
		systems.

		Both required and optional properties listed below must be defined
		under node /cpus/cpu@x. Where x is the first cpu inside a cluster.

		FIXME: Cpus should boot in the order specified in DT and all cpus for a cluster
		must be present contiguously. Generic DT driver will check only node 'x' for
		cpu:x.

		Required properties:
		- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
		for details

		Optional properties:
		- clock-latency: Specify the possible maximum transition latency for clock,
		in unit of nanoseconds.

		Examples:

		cpus {
		#address-cells = <1>;
		#size-cells = <0>;

		cpu@0 {
		compatible = "arm,cortex-a15";
		reg = <0>;
		next-level-cache = <&L2>;
		operating-points = <
		/* kHz uV */
		792000 1100000
		396000 950000
		198000 850000
		>;
		clock-latency = <61036>; /* two CLK32 periods */
		};

		cpu@1 {
		compatible = "arm,cortex-a15";
		reg = <1>;
		next-level-cache = <&L2>;
		};

		cpu@100 {
		compatible = "arm,cortex-a7";
		reg = <100>;
		next-level-cache = <&L2>;
		operating-points = <
		/* kHz uV */
		792000 950000
		396000 750000
		198000 450000
		>;
		clock-latency = <61036>; /* two CLK32 periods */
		};

		cpu@101 {
		compatible = "arm,cortex-a7";
		reg = <101>;
		next-level-cache = <&L2>;
		};
		};

Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt

+1 −1

Original line number	Diff line number	Diff line
		@@ -32,7 +32,7 @@ cpus {
		396000 950000
		198000 850000
		>;
		transition-latency = <61036>; /* two CLK32 periods */
		clock-latency = <61036>; /* two CLK32 periods */
		};

		cpu@1 {

Documentation/devicetree/bindings/cpufreq/cpufreq-exynos5440.txt

0 → 100644

+28 −0

Original line number	Diff line number	Diff line

		Exynos5440 cpufreq driver
		-------------------

		Exynos5440 SoC cpufreq driver for CPU frequency scaling.

		Required properties:
		- interrupts: Interrupt to know the completion of cpu frequency change.
		- operating-points: Table of frequencies and voltage CPU could be transitioned into,
		in the decreasing order. Frequency should be in KHz units and voltage
		should be in microvolts.

		Optional properties:
		- clock-latency: Clock monitor latency in microsecond.

		All the required listed above must be defined under node cpufreq.

		Example:
		--------
		cpufreq@160000 {
		compatible = "samsung,exynos5440-cpufreq";
		reg = <0x160000 0x1000>;
		interrupts = <0 57 0>;
		operating-points = <
		1000000 975000
		800000 925000>;
		clock-latency = <100000>;
		};

Admin message