[PATCH 2/8] cpufreq: Fix misplaced call to cpufreq_update_policy()

From: Srivatsa S. Bhat
Date: Thu Jul 11 2013 - 18:19:33 EST


The call to cpufreq_update_policy() is placed in the CPU hotplug callback
of cpufreq_stats, which has a higher priority than the CPU hotplug callback
of cpufreq-core. As a result, during CPU_ONLINE/CPU_ONLINE_FROZEN, we end up
calling cpufreq_update_policy() *before* calling cpufreq_add_dev() !
And for uninitialized CPUs, it just returns silently, not doing anything.

To add to it, cpufreq_stats is not even the right place to call
cpufreq_update_policy() to begin with. The cpufreq core ought to handle
this in its own callback, from an elegance/relevance perspective.

So move the invocation of cpufreq_update_policy() to cpufreq_cpu_callback,
and place it *after* cpufreq_add_dev().

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---

drivers/cpufreq/cpufreq.c | 1 +
drivers/cpufreq/cpufreq_stats.c | 6 ------
2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ccc6eab..f8c3100 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1943,6 +1943,7 @@ static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
cpufreq_add_dev(dev, NULL);
+ cpufreq_update_policy(cpu);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 12225d1..a3e7475 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -348,10 +348,6 @@ static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
unsigned int cpu = (unsigned long)hcpu;

switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- cpufreq_update_policy(cpu);
- break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
cpufreq_stats_free_sysfs(cpu);
@@ -390,8 +386,6 @@ static int __init cpufreq_stats_init(void)
return ret;

register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
- for_each_online_cpu(cpu)
- cpufreq_update_policy(cpu);

ret = cpufreq_register_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);

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