path: root/Documentation/cpu-freq/user-guide.txt
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Diffstat (limited to 'Documentation/cpu-freq/user-guide.txt')
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
index 2a5b850847c0..04f6b32993e6 100644
--- a/Documentation/cpu-freq/user-guide.txt
+++ b/Documentation/cpu-freq/user-guide.txt
@@ -203,6 +203,17 @@ scaling_cur_freq : Current frequency of the CPU as determined by
the frequency the kernel thinks the CPU runs
+bios_limit : If the BIOS tells the OS to limit a CPU to
+ lower frequencies, the user can read out the
+ maximum available frequency from this file.
+ This typically can happen through (often not
+ intended) BIOS settings, restrictions
+ triggered through a service processor or other
+ BIOS/HW based implementations.
+ This does not cover thermal ACPI limitations
+ which can be detected through the generic
+ thermal driver.
If you have selected the "userspace" governor which allows you to
set the CPU operating frequency to a specific value, you can read out
the current frequency in