[PATCH 0/2] Add exit_prepare callback to the cpufreq_driver interface.

From: dirk . brandewie
Date: Thu Mar 13 2014 - 13:37:04 EST


From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>

Some drivers (intel_pstate) need to modify state on a core before it
is completely offline. The ->exit() callback is executed during the
CPU_POST_DEAD phase of the cpu offline process which is too late to
change the state of the core.

Patch 1 adds an optional callback function to the cpufreq_driver
interface which is called by the core during the CPU_DOWN_PREPARE
phase of cpu offline in __cpufreq_remove_dev_prepare().

Patch 2 changes intel_pstate to use the ->exit_prepare callback to do
its cleanup during cpu offline.

Dirk Brandewie (2):
cpufreq: Add exit_prepare callback to cpufreq_driver interface
intel_pstate: Set core to min P state during core offline

Documentation/cpu-freq/cpu-drivers.txt | 8 +++++++-
drivers/cpufreq/cpufreq.c | 3 +++
drivers/cpufreq/intel_pstate.c | 20 +++++++++++++-------
include/linux/cpufreq.h | 1 +
4 files changed, 24 insertions(+), 8 deletions(-)

--
1.8.3.1

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