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Subject[ 021/103] cpufreq: Revert commit a66b2e to fix suspend/resume regression
Date
3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>

commit aae760ed21cd690fe8a6db9f3a177ad55d7e12ab upstream.

commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume)
has unfortunately caused several things in the cpufreq subsystem to
break subtly after a suspend/resume cycle.

The intention of that patch was to retain the file permissions of the
cpufreq related sysfs files across suspend/resume. To achieve that,
the commit completely removed the calls to cpufreq_add_dev() and
__cpufreq_remove_dev() during suspend/resume transitions. But the
problem is that those functions do 2 kinds of things:
1. Low-level initialization/tear-down that are critical to the
correct functioning of cpufreq-core.
2. Kobject and sysfs related initialization/teardown.

Ideally we should have reorganized the code to cleanly separate these
two responsibilities, and skipped only the sysfs related parts during
suspend/resume. Since we skipped the entire callbacks instead (which
also included some CPU and cpufreq-specific critical components),
cpufreq subsystem started behaving erratically after suspend/resume.

So revert the commit to fix the regression. We'll revisit and address
the original goal of that commit separately, since it involves quite a
bit of careful code reorganization and appears to be non-trivial.

(While reverting the commit, note that another commit f51e1eb
(cpufreq: Fix cpufreq regression after suspend/resume) already
reverted part of the original set of changes. So revert only the
remaining ones).

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/cpufreq/cpufreq.c | 4 +++-
drivers/cpufreq/cpufreq_stats.c | 6 ++----
2 files changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1837,13 +1837,15 @@ static int __cpuinit cpufreq_cpu_callbac
if (dev) {
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cpufreq_add_dev(dev, NULL);
break;
case CPU_DOWN_PREPARE:
- case CPU_UP_CANCELED_FROZEN:
+ case CPU_DOWN_PREPARE_FROZEN:
__cpufreq_remove_dev(dev, NULL);
break;
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
cpufreq_add_dev(dev, NULL);
break;
}
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -353,13 +353,11 @@ static int __cpuinit cpufreq_stat_cpu_ca
cpufreq_update_policy(cpu);
break;
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
cpufreq_stats_free_sysfs(cpu);
break;
case CPU_DEAD:
- cpufreq_stats_free_table(cpu);
- break;
- case CPU_UP_CANCELED_FROZEN:
- cpufreq_stats_free_sysfs(cpu);
+ case CPU_DEAD_FROZEN:
cpufreq_stats_free_table(cpu);
break;
}



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