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Code Issues Releases Wiki Activity

[CPUFREQ] S5PV210: Lock a mutex while changing the cpu frequency

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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>
This commit is contained in:
Arve Hjønnevåg 2011-06-24 16:04:16 +09:00 committed by Dave Jones
parent 405e6d6df7
commit 5b02b7794b
1 changed files with 19 additions and 9 deletions
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28
drivers/cpufreq/s5pv210-cpufreq.c
View file

@ -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