From 3e45cd20962667f2afbd9fefccb91494ecc4ab5f Mon Sep 17 00:00:00 2001
From: Nishanth Menon <nm@ti.com>
Date: Thu, 26 May 2011 19:39:20 -0700
Subject: [PATCH 15/19] OMAP2+: cpufreq: fix freq_table leak

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@ti.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
---
 arch/arm/mach-omap2/omap2plus-cpufreq.c |   22 +++++++++++++++++-----
 1 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-omap2/omap2plus-cpufreq.c b/arch/arm/mach-omap2/omap2plus-cpufreq.c
index e019297..a962a31 100644
--- a/arch/arm/mach-omap2/omap2plus-cpufreq.c
+++ b/arch/arm/mach-omap2/omap2plus-cpufreq.c
@@ -39,6 +39,7 @@
 #include <mach/hardware.h>
 
 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;
@@ -153,6 +154,12 @@ skip_lpj:
 	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;
@@ -168,7 +175,9 @@ 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",
@@ -177,10 +186,10 @@ 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;
@@ -204,6 +213,8 @@ 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;
@@ -211,6 +222,7 @@ fail_ck:
 
 static int omap_cpu_exit(struct cpufreq_policy *policy)
 {
+	freq_table_free();
 	clk_put(mpu_clk);
 	return 0;
 }
-- 
1.6.6.1

