Jan 03 2013

MIPS: Loongson2: Use clk API instead of direct dereferences 

Author: Julia Lawall <Julia.Lawall@lip6.fr>

A struct clk value is intended to be an abstract pointer, so it should be
manipulated using the various API functions.

clk_put is additionally added on the failure paths.

The semantic match that finds the first problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
expression e,e1;
identifier i;
@@

*e = clk_get(...)
 ... when != e = e1
     when any
*e->i
// 

Signed-off-by: Julia Lawall 
Cc: kernel-janitors@vger.kernel.org
Cc: linux-mips@linux-mips.org,
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4751/
Signed-off-by: Ralf Baechle 

---
 arch/mips/kernel/cpufreq/loongson2_cpufreq.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)
 
diff --git a/arch/mips/kernel/cpufreq/loongson2_cpufreq.c b/arch/mips/kernel/cpufreq/loongson2_cpufreq.c
index bb51d31..3237c52 100644
--- a/arch/mips/kernel/cpufreq/loongson2_cpufreq.c
+++ b/arch/mips/kernel/cpufreq/loongson2_cpufreq.c
@@ -107,6 +107,8 @@ static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
 static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	int i;
+	unsigned long rate;
+	int ret;
 
 	if (!cpu_online(policy->cpu))
 		return -ENODEV;
@@ -117,15 +119,22 @@ static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		return PTR_ERR(cpuclk);
 	}
 
-	cpuclk->rate = cpu_clock_freq / 1000;
-	if (!cpuclk->rate)
+	rate = cpu_clock_freq / 1000;
+	if (!rate) {
+		clk_put(cpuclk);
 		return -EINVAL;
+	}
+	ret = clk_set_rate(cpuclk, rate);
+	if (ret) {
+		clk_put(cpuclk);
+		return ret;
+	}
 
 	/* clock table init */
 	for (i = 2;
 	     (loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
 	     i++)
-		loongson2_clockmod_table[i].frequency = (cpuclk->rate * i) / 8;
+		loongson2_clockmod_table[i].frequency = (rate * i) / 8;
 
 	policy->cur = loongson2_cpufreq_get(policy->cpu);

qlambert