This patchset adds cpufreq callbacks to dpm_{suspend|resume}() for handling
suspend/resume of cpufreq governors and core. This is required for early suspend
and late resume of governors and cpufreq 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. Most of these are updated in this
patchset to use new infrastructure.
- Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found another 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 also fixed with this patch as don't
allow any operation on Governors during suspend/resume now.
So to solve these issues we introduce early suspend and late resume callbacks
which would remove need of cpufreq drivers to implement PM notifiers to disable
transition after suspend and before resume.
@Nishanth: Can you please test V2 as well and confirm that suspend_noirq()
doesn't work for you. I am sure it will not, but would be better if you confirm
that.
Viresh Kumar (6):
cpufreq: suspend governors on system suspend/hibernate
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 | 133 +++++++++++++++++++++-----------------
drivers/cpufreq/exynos-cpufreq.c | 97 ++-------------------------
drivers/cpufreq/s5pv210-cpufreq.c | 49 +-------------
drivers/cpufreq/tegra-cpufreq.c | 54 ++--------------
include/linux/cpufreq.h | 6 ++
6 files changed, 99 insertions(+), 245 deletions(-)
--
1.7.12.rc2.18.g61b472e
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