[PATCH V6 0/7] cpufreq: suspend early/resume late: dpm_{suspend|resume}()

Viresh Kumar
2014-02-17T09:25:26Z

This patchset creates/calls cpufreq suspend/resume callbacks from dpm_{suspend|resume}()
for handling suspend/resume of cpufreq governors and core.

There are multiple problems that are fixed by this patch:
- Nishanth Menon (TI) found an interesting problem on his platform, OMAP. His board
wasn't working well with suspend/resume as calls for removing non-boot CPUs
was turning out into a call to drivers ->target() which then tries to play
with regulators. But regulators and their I2C bus were already suspended and
this resulted in a failure. Many platforms have such problems, samsung, tegra,
etc.. They solved it with driver specific PM notifiers where they used to
disable their driver's ->target() routine.
- Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found an issue where tunables
configuration for clusters/sockets with non-boot CPUs was getting lost after
suspend/resume, as we were notifying governors with CPUFREQ_GOV_POLICY_EXIT on
removal of the last cpu for that policy and so deallocating memory for
tunables. This is fixed by this patch as we don't allow any operation on
governors after device suspend and before device resume now.

This is already tested by few people and so incorporating their Tested-by as
well.

I have tested this again on latest stuff on my thinkpad for several
suspend/resume cycles.

V6->V7:
- Fixed crash reported by S.Warren on systems without a cpufreq driver.
- Moved some function doc-comments to patch 1 from a later patch.

For-v3.15

Viresh Kumar (7):
cpufreq: suspend governors on system suspend/hibernate
cpufreq: suspend governors from dpm_{suspend|resume}()
cpufreq: call driver's suspend/resume for each policy
cpufreq: Implement cpufreq_generic_suspend()
cpufreq: exynos: Use cpufreq_generic_suspend()
cpufreq: s5pv210: Use cpufreq_generic_suspend()
cpufreq: Tegra: Use cpufreq_generic_suspend()

drivers/base/power/main.c | 5 ++
drivers/cpufreq/cpufreq.c | 137 +++++++++++++++++++++++---------------
drivers/cpufreq/exynos-cpufreq.c | 96 ++------------------------
drivers/cpufreq/s5pv210-cpufreq.c | 49 +-------------
drivers/cpufreq/tegra-cpufreq.c | 46 ++-----------
include/linux/cpufreq.h | 11 +++
6 files changed, 113 insertions(+), 231 deletions(-)

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1.7.12.rc2.18.g61b472e