hwmon: (smsc47m192) Fix temperature limit and vrm write operations

Temperature limit clamps are applied after converting the temperature
from milli-degrees C to degrees C, so either the clamp limit needs
to be specified in degrees C, not milli-degrees C, or clamping must
happen before converting to degrees C. Use the latter method to avoid
overflows.

vrm is an u8, so the written value needs to be limited to [0, 255].

Cc: Axel Lin <axel.lin@ingics.com>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>

diff --git a/drivers/hwmon/smsc47m192.c b/drivers/hwmon/smsc47m192.c
index efee4c59239fcff8aa7b675c01cb5b9ac6bab5bd..34b9a601ad078c394513e67a5dccc345c6c02fef 100644 (file)
--- a/drivers/hwmon/smsc47m192.c
+++ b/drivers/hwmon/smsc47m192.c
@@ -86,7 +86,7 @@ static inline u8 IN_TO_REG(unsigned long val, int n)
  */
 static inline s8 TEMP_TO_REG(int val)
 {
-       return clamp_val(SCALE(val, 1, 1000), -128000, 127000);
+       return SCALE(clamp_val(val, -128000, 127000), 1, 1000);
 }
 
 static inline int TEMP_FROM_REG(s8 val)
@@ -384,6 +384,8 @@ static ssize_t set_vrm(struct device *dev, struct device_attribute *attr,
        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;
+       if (val > 255)
+               return -EINVAL;
 
        data->vrm = val;
        return count;