[PATCH 2/3] cpufreq: ppc: Fix integer overflow in expression

From: Geert Uytterhoeven
Date: Thu Apr 17 2014 - 05:53:48 EST


On 32-bit, "12 * NSEC_PER_SEC" doesn't fit in "unsigned long"
(NSEC_PER_SEC is a "long" constant), causing an integer overflow:

drivers/cpufreq/ppc-corenet-cpufreq.c: In function 'corenet_cpufreq_cpu_init':
drivers/cpufreq/ppc-corenet-cpufreq.c:211:9: warning: integer overflow in expression [-Woverflow]

Force the intermediate to be 64-bit by adding an "ULL" suffix to the
constant multiplier to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/cpufreq/ppc-corenet-cpufreq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
index e78f9c806de4..53881d78a931 100644
--- a/drivers/cpufreq/ppc-corenet-cpufreq.c
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -208,7 +208,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
per_cpu(cpu_data, i) = data;

policy->cpuinfo.transition_latency =
- (12 * NSEC_PER_SEC) / fsl_get_sys_freq();
+ (12ULL * NSEC_PER_SEC) / fsl_get_sys_freq();
of_node_put(np);

return 0;
--
1.7.9.5

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