[lm-sensors] [PATCH] hwmon: (gpio-fan) Prevent overflow problem when writing large limits

[lm-sensors] [PATCH] hwmon: (gpio-fan) Prevent overflow problem when writing large limits

[Axel Lin]

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>
---
 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 a43e5b0..4efa173 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




_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors

Re: [lm-sensors] [PATCH] hwmon: (gpio-fan) Prevent overflow problem when writing large limits

[Guenter Roeck]

On 08/01/2014 10:36 PM, Axel Lin wrote:
> 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>

Good catch. Applied.

Thanks,
Guenter



_______________________________________________
lm-sensors mailing list
lm-sensors@lm-sensors.org
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors