[PATCH 3.13 142/187] hwmon: (gpio-fan) Prevent overflow problem when writing large limits

[Kamal Mostafa]

3.13.11.7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Axel Lin <axel.lin at ingics.com>

commit 2565fb05d1e9fc0831f7b1c083bcfcb1cba1f020 upstream.

On platforms with sizeof(int) < sizeof(unsigned long), writing a rpm value
larger than MAXINT will result in unpredictable limit values written to the
chip. Avoid auto-conversion from unsigned long to int to fix the problem.

Signed-off-by: Axel Lin <axel.lin at ingics.com>
Signed-off-by: Guenter Roeck <linux at roeck-us.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/hwmon/gpio-fan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index 73181be..814f7ee 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -173,7 +173,7 @@ static int get_fan_speed_index(struct gpio_fan_data *fan_data)
 	return -ENODEV;
 }
 
-static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int rpm)
+static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
 {
 	struct gpio_fan_speed *speed = fan_data->speed;
 	int i;
-- 
1.9.1