From: Soohyun Kim <soohyuni.kim@samsung.com>
Date: Fri, 30 Mar 2018 10:16:27 +0000 (+0900)
Subject: cpufreq: acme: fix race contidion when set/get freq.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4640368983989ec7c72dc24e8342405d65a6c9e3;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

cpufreq: acme: fix race contidion when set/get freq.

Change-Id: I7a7d59366d81ae4544760548dbb8fac4fed5abe0
Signed-off-by: Soohyun Kim <soohyuni.kim@samsung.com>
---

diff --git a/drivers/cpufreq/exynos-acme.c b/drivers/cpufreq/exynos-acme.c
index a5af5b602c81..58661b628ca9 100644
--- a/drivers/cpufreq/exynos-acme.c
+++ b/drivers/cpufreq/exynos-acme.c
@@ -144,8 +144,9 @@ static unsigned int get_freq(struct exynos_cpufreq_domain *domain)
 {
 	unsigned int freq;
 
-	if (domain->need_awake)
-		disable_power_mode(cpumask_any(&domain->cpus), POWERMODE_TYPE_CLUSTER);
+	if (domain->need_awake &&
+		check_powerdown_state(cpumask_any(&domain->cpus), POWERMODE_TYPE_CLUSTER))
+		return domain->old;
 
 	freq = (unsigned int)cal_dfs_get_rate(domain->cal_id);
 	if (!freq) {
@@ -153,9 +154,6 @@ static unsigned int get_freq(struct exynos_cpufreq_domain *domain)
 		freq = domain->old;
 	}
 
-	if (domain->need_awake)
-		enable_power_mode(cpumask_any(&domain->cpus), POWERMODE_TYPE_CLUSTER);
-
 	return freq;
 }
 
diff --git a/drivers/soc/samsung/exynos-cpupm.c b/drivers/soc/samsung/exynos-cpupm.c
index 5eb9f67ce4d3..a25bea07a7af 100644
--- a/drivers/soc/samsung/exynos-cpupm.c
+++ b/drivers/soc/samsung/exynos-cpupm.c
@@ -422,6 +422,25 @@ struct exynos_cpupm {
 
 static DEFINE_PER_CPU(struct exynos_cpupm, cpupm);
 
+int check_powerdown_state(int cpu, int type)
+{
+	struct exynos_cpupm *pm;
+	struct power_mode *mode;
+	int pos;
+
+	pm = &per_cpu(cpupm, cpu);
+
+	for_each_mode(mode, pm->modes, pos) {
+		if (IS_NULL(mode))
+			break;
+
+		if (mode->type == type)
+			return check_state_powerdown(mode);
+	}
+
+	return 0;
+}
+
 /*
  * State of each cpu is managed by a structure declared by percpu, so there
  * is no need for protection for synchronization. However, when entering
@@ -455,6 +474,8 @@ void disable_power_mode(int cpu, int type)
 	struct power_mode *mode;
 	int pos;
 
+	spin_lock(&cpupm_lock);
+
 	pm = &per_cpu(cpupm, cpu);
 
 	for_each_mode(mode, pm->modes, pos) {
@@ -473,10 +494,14 @@ void disable_power_mode(int cpu, int type)
 			 * The first mode disable request wakes the cpus to
 			 * exit power mode
 			 */
-			if (atomic_inc_return(&mode->disable) == 1)
+			if (atomic_inc_return(&mode->disable) == 1) {
+				spin_unlock(&cpupm_lock);
 				awake_cpus(&mode->siblings);
+				return;
+			}
 		}
 	}
+	spin_unlock(&cpupm_lock);
 }
 
 void enable_power_mode(int cpu, int type)
@@ -485,6 +510,7 @@ void enable_power_mode(int cpu, int type)
 	struct power_mode *mode;
 	int pos;
 
+	spin_lock(&cpupm_lock);
 	pm = &per_cpu(cpupm, cpu);
 
 	for_each_mode(mode, pm->modes, pos) {
@@ -494,6 +520,7 @@ void enable_power_mode(int cpu, int type)
 		if (mode->type == type)
 			atomic_dec(&mode->disable);
 	}
+	spin_unlock(&cpupm_lock);
 }
 
 /* get sleep length of given cpu from tickless framework */
diff --git a/include/soc/samsung/exynos-cpupm.h b/include/soc/samsung/exynos-cpupm.h
index 0914f0557062..9610b14face7 100644
--- a/include/soc/samsung/exynos-cpupm.h
+++ b/include/soc/samsung/exynos-cpupm.h
@@ -19,6 +19,7 @@ enum {
 
 extern void disable_power_mode(int cpu, int type);
 extern void enable_power_mode(int cpu, int type);
+extern int check_powerdown_state(int cpu, int type);
 
 #ifdef CONFIG_CPU_IDLE
 void exynos_update_ip_idle_status(int index, int idle);