Hi Rafael,
You recently did this:
commit 878f6e074e9a7784a6e351512eace4ccb3542eef
Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Date: Sun Aug 18 15:35:59 2013 +0200
Revert "cpufreq: Use cpufreq_policy_list for iterating over policies"
Revert commit eb60852 (cpufreq: Use cpufreq_policy_list for iterating
over policies), because it breaks system suspend/resume on multiple
machines.
It either causes resume to block indefinitely or causes the BUG_ON()
in lock_policy_rwsem_##mode() to trigger on sysfs accesses to cpufreq
attributes.
------x------------x---------------
This patchset gets the reverted patch back along with few supporting patches.
Cause of the initial problem you observed was this:
- At suspend all CPUs are removed leaving boot cpu. At this time policies aren't
freed and also aren't removed from cpufreq_policy_list. And per-cpu variable
cpufreq_cpu_data is marked as NULL.
- At resume CPUs other than boot cpu called __cpufreq_add_dev(). The tricky
change that was introduced by my patch was: We iterate over list of policies
instead of CPUs, where we used to get policy structure associated with
CPUs using per-cpu variable. Which used to be NULL for first CPU of a policy
that turned up. For the first cpu we don't want to call
cpufreq_add_policy_cpu() but want __cpufreq_add_add() to continue.
When we called cpufreq_add_policy_cpu() it tried to stop the governor (which
was already stopped) and hence errors leading into unstable state.
This patchset fixes these issues and is tested with suspend-resume over my
thinkpad with ubuntu. Apart from minor cleanups it removes policy from
cpufreq_policy_list in case of suspend/resume as well and hence we will never
call cpufreq_add_policy_cpu() for first cpu of a policy.
--
viresh
Viresh Kumar (5):
cpufreq: align closing brace '}' of an if block
cpufreq: remove policy from cpufreq_policy_list in system suspend
cpufreq: remove unnecessary check in __cpufreq_governor()
cpufreq: remove cpufreq_policy_cpu per-cpu variable
cpufreq: Use cpufreq_policy_list for iterating over policies
drivers/cpufreq/cpufreq.c | 77 +++++++++++++++--------------------------------
1 file changed, 24 insertions(+), 53 deletions(-)
--
1.7.12.rc2.18.g61b472e
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