From: Pan Xinhui <xinhuix.pan@intel.com>
Date: Fri, 10 Jul 2015 06:36:20 +0000 (+0800)
Subject: acpi-cpufreq: Fix an ACPI perf unregister issue
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=8cfcfd39000d;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git

acpi-cpufreq: Fix an ACPI perf unregister issue

As policy->cpu may not be same in acpi_cpufreq_cpu_init() and
acpi_cpufreq_cpu_exit(). There is a risk that we use different CPU
to un/register ACPI performance. So acpi_processor_unregister_performance()
may not be able to do the cleanup work. That causes a memory leak. And
if there will be another acpi_processor_register_performance() call,
it may also fail thanks to the internal check of pr->performace.

So add a new struct acpi_cpufreq_data field, acpi_perf_cpu, to fix
this issue.

Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index e7fcaa6eedbd..de54ce14eb39 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -69,6 +69,7 @@ struct acpi_cpufreq_data {
 	struct cpufreq_frequency_table *freq_table;
 	unsigned int resume;
 	unsigned int cpu_feature;
+	unsigned int acpi_perf_cpu;
 	cpumask_var_t freqdomain_cpus;
 };
 
@@ -677,6 +678,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	}
 
 	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
+	data->acpi_perf_cpu = cpu;
 	policy->driver_data = data;
 
 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
@@ -861,7 +863,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 	if (data) {
 		policy->driver_data = NULL;
 		acpi_processor_unregister_performance(data->acpi_data,
-						      policy->cpu);
+						      data->acpi_perf_cpu);
 		free_cpumask_var(data->freqdomain_cpus);
 		kfree(data->freq_table);
 		kfree(data);