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Commit 39a74fde authored by Shaohua Li's avatar Shaohua Li Committed by Len Brown
Browse files

intel_idle: fix API misuse 



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: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 805a6af8

drivers/idle/intel_idle.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

	}