path: root/Documentation/cpu-freq
diff options
authorDirk Brandewie <>2014-03-19 08:45:53 -0700
committerRafael J. Wysocki <>2014-03-20 03:50:12 +0100
commit367dc4aa932bfb33a3189064d33f7890a8ec1ca8 (patch)
treefde9bd6004ff7852da144a373dd1c0536521efef /Documentation/cpu-freq
parentbda9f552f9826313ef8a477fc8e4891de9ae5e73 (diff)
cpufreq: Add stop CPU callback to cpufreq_driver interface
This callback allows the driver to do clean up before the CPU is completely down and its state cannot be modified. This is used by the intel_pstate driver to reduce the requested P state prior to the core going away. This is required because the requested P state of the offline core is used to select the package P state. This effectively sets the floor package P state to the requested P state on the offline core. Signed-off-by: Dirk Brandewie <> [rjw: Minor modifications] Signed-off-by: Rafael J. Wysocki <>
Diffstat (limited to 'Documentation/cpu-freq')
1 files changed, 7 insertions, 1 deletions
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt
index 8b1a4451422e..48da5fdcb9f1 100644
--- a/Documentation/cpu-freq/cpu-drivers.txt
+++ b/Documentation/cpu-freq/cpu-drivers.txt
@@ -61,7 +61,13 @@ target_index - See below on the differences.
And optionally
-cpufreq_driver.exit - A pointer to a per-CPU cleanup function.
+cpufreq_driver.exit - A pointer to a per-CPU cleanup
+ function called during CPU_POST_DEAD
+ phase of cpu hotplug process.
+cpufreq_driver.stop_cpu - A pointer to a per-CPU stop function
+ called during CPU_DOWN_PREPARE phase of
+ cpu hotplug process.
cpufreq_driver.resume - A pointer to a per-CPU resume function
which is called with interrupts disabled