[PATCH 3.10 19/55] hwmon: (gpio-fan) Prevent overflow problem when writing large limits

Greg Kroah-Hartman
2014-09-03T23:48:03Z

From: Axel Lin <axel.lin@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@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hwmon/gpio-fan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -172,7 +172,7 @@ static int get_fan_speed_index(struct gp
return -EINVAL;
}

-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;