From: Nishanth Menon <nm@xxxxxx>
We use a single frequency table for multiple CPUs. But, with
OMAP4, since we have multiple CPUs, the cpu_init call for CPU1
causes freq_table previously allocated for CPU0 to be overwritten.
In addition, we dont free the table on exit path.
We solve this by maintaining an atomic type counter to ensure
just a single table exists at a given time.
Signed-off-by: Nishanth Menon <nm@xxxxxx>
Signed-off-by: Kevin Hilman <khilman@xxxxxx>
---
drivers/cpufreq/omap-cpufreq.c | 22 +++++++++++++++++-----
1 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index a66c8b5..90918e1 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -45,6 +45,7 @@ static struct lpj_info global_lpj_ref;
#endif
static struct cpufreq_frequency_table *freq_table;
+static atomic_t freq_table_users = ATOMIC_INIT(0);
static struct clk *mpu_clk;
static char *mpu_clk_name;
static struct device *mpu_dev;
@@ -149,6 +150,12 @@ static int omap_target(struct cpufreq_policy *policy,
return ret;
}
+static inline void freq_table_free(void)
+{
+ if (atomic_dec_and_test(&freq_table_users))
+ opp_free_cpufreq_table(mpu_dev, &freq_table);
+}
+
static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
{
int result = 0;
@@ -163,7 +170,9 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
}
policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu);
- result = opp_init_cpufreq_table(mpu_dev, &freq_table);
+
+ if (atomic_inc_return(&freq_table_users) == 1)
+ result = opp_init_cpufreq_table(mpu_dev, &freq_table);
if (result) {
dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n",
@@ -172,10 +181,10 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
}
result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
- if (!result)
- cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
- else
- goto fail_ck;
+ if (result)
+ goto fail_table;
+
+ cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
policy->min = policy->cpuinfo.min_freq;
policy->max = policy->cpuinfo.max_freq;
@@ -198,6 +207,8 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
return 0;
+fail_table:
+ freq_table_free();
fail_ck:
clk_put(mpu_clk);
return result;
@@ -205,6 +216,7 @@ fail_ck:
static int omap_cpu_exit(struct cpufreq_policy *policy)
{
+ freq_table_free();
clk_put(mpu_clk);
return 0;
}
--
1.7.6
--
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