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Subject[PATCH 43/50] intel_idle: fix API misuse
Date
From: Shaohua Li <shaohua.li@intel.com>

smp_call_function() only lets all other CPUs execute a specific function,
while we expect all CPUs do in intel_idle. Without the fix, we could have
one cpu which has auto_demotion enabled or has no broadcast timer setup.
Usually we don't see impact because auto demotion just harms power and the
intel_idle init is called in CPU 0, where boradcast timer delivers
interrupt, but this still could be a problem.

Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/idle/intel_idle.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 5d2f8e1..af0b4a5 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -394,7 +394,7 @@ static int intel_idle_probe(void)
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
else {
- smp_call_function(__setup_broadcast_timer, (void *)true, 1);
+ on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
register_cpu_notifier(&setup_broadcast_notifier);
}

@@ -471,7 +471,7 @@ static int intel_idle_cpuidle_driver_init(void)
}

if (auto_demotion_disable_flags)
- smp_call_function(auto_demotion_disable, NULL, 1);
+ on_each_cpu(auto_demotion_disable, NULL, 1);

return 0;
}
@@ -568,7 +568,7 @@ static void __exit intel_idle_exit(void)
cpuidle_unregister_driver(&intel_idle_driver);

if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) {
- smp_call_function(__setup_broadcast_timer, (void *)false, 1);
+ on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
unregister_cpu_notifier(&setup_broadcast_notifier);
}

--
1.7.9.rc1


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