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authorArve Hjønnevåg <arve@android.com>2011-06-24 16:04:16 +0900
committerDave Jones <davej@redhat.com>2011-07-13 18:29:58 -0400
commit5b02b7794b555e299c5e9298c6b223b538888ec8 (patch)
treeae2abbea1e4fc0ac98a544d058c3d0689b01cef0 /drivers/cpufreq
parent405e6d6df739a27a267b381213aa9e86c4929543 (diff)
[CPUFREQ] S5PV210: Lock a mutex while changing the cpu frequency
Without this lock the call to change the frequency for suspend could switch to a new frequency while another thread was still changing the cpu voltage. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/s5pv210-cpufreq.c28
1 files changed, 19 insertions, 9 deletions
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 79b1b4ec8e3c..7fba356d2729 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -26,6 +26,7 @@ static struct clk *cpu_clk;
static struct clk *dmc0_clk;
static struct clk *dmc1_clk;
static struct cpufreq_freqs freqs;
+static DEFINE_MUTEX(set_freq_lock);
/* APLL M,P,S values for 1G/800Mhz */
#define APLL_VAL_1000 ((1 << 31) | (125 << 16) | (3 << 8) | 1)
@@ -199,6 +200,8 @@ static int s5pv210_target(struct cpufreq_policy *policy,
int arm_volt, int_volt;
int ret = 0;
+ mutex_lock(&set_freq_lock);
+
if (relation & ENABLE_FURTHER_CPUFREQ)
no_cpufreq_access = false;
@@ -207,7 +210,8 @@ static int s5pv210_target(struct cpufreq_policy *policy,
pr_err("%s:%d denied access to %s as it is disabled"
"temporarily\n", __FILE__, __LINE__, __func__);
#endif
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit;
}
if (relation & DISABLE_FURTHER_CPUFREQ)
@@ -218,19 +222,23 @@ static int s5pv210_target(struct cpufreq_policy *policy,
freqs.old = s5pv210_getspeed(0);
if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
- target_freq, relation, &index))
- return -EINVAL;
+ target_freq, relation, &index)) {
+ ret = -EINVAL;
+ goto exit;
+ }
freqs.new = s5pv210_freq_table[index].frequency;
freqs.cpu = 0;
if (freqs.new == freqs.old)
- return 0;
+ goto exit;
/* Finding current running level index */
if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
- freqs.old, relation, &priv_index))
- return -EINVAL;
+ freqs.old, relation, &priv_index)) {
+ ret = -EINVAL;
+ goto exit;
+ }
arm_volt = dvs_conf[index].arm_volt;
int_volt = dvs_conf[index].int_volt;
@@ -239,12 +247,12 @@ static int s5pv210_target(struct cpufreq_policy *policy,
ret = regulator_set_voltage(arm_regulator,
arm_volt, arm_volt_max);
if (ret)
- return ret;
+ goto exit;
ret = regulator_set_voltage(int_regulator,
int_volt, int_volt_max);
if (ret)
- return ret;
+ goto exit;
}
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
@@ -471,7 +479,9 @@ static int s5pv210_target(struct cpufreq_policy *policy,
printk(KERN_DEBUG "Perf changed[L%d]\n", index);
- return 0;
+exit:
+ mutex_unlock(&set_freq_lock);
+ return ret;
}
#ifdef CONFIG_PM