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-rw-r--r--Documentation/cpu-freq/user-guide.txt28
1 files changed, 12 insertions, 16 deletions
diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
index e3443ddcfb8..75f41193f3e 100644
--- a/Documentation/cpu-freq/user-guide.txt
+++ b/Documentation/cpu-freq/user-guide.txt
@@ -152,6 +152,18 @@ cpuinfo_min_freq : this file shows the minimum operating
frequency the processor can run at(in kHz)
cpuinfo_max_freq : this file shows the maximum operating
frequency the processor can run at(in kHz)
+cpuinfo_transition_latency The time it takes on this CPU to
+ switch between two frequencies in nano
+ seconds. If unknown or known to be
+ that high that the driver does not
+ work with the ondemand governor, -1
+ (CPUFREQ_ETERNAL) will be returned.
+ Using this information can be useful
+ to choose an appropriate polling
+ frequency for a kernel governor or
+ userspace daemon. Make sure to not
+ switch the frequency too often
+ resulting in performance loss.
scaling_driver : this file shows what cpufreq driver is
used to set the frequency on this CPU
@@ -195,19 +207,3 @@ scaling_setspeed. By "echoing" a new frequency into this
you can change the speed of the CPU,
but only within the limits of
scaling_min_freq and scaling_max_freq.
-
-
-3.2 Deprecated Interfaces
--------------------------
-
-Depending on your kernel configuration, you might find the following
-cpufreq-related files:
-/proc/cpufreq
-/proc/sys/cpu/*/speed
-/proc/sys/cpu/*/speed-min
-/proc/sys/cpu/*/speed-max
-
-These are files for deprecated interfaces to cpufreq, which offer far
-less functionality. Because of this, these interfaces aren't described
-here.
-