1 files changed, 11 insertions, 0 deletions

diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt
index 2a5b850847c..04f6b32993e 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
                                 at.
 
+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