hwmon: (emc2103) Fix use of an uninitilized variable in error case

Fix:

emc2103.c: In function set_pwm_enable:
emc2103.c:463:12: warning: conf_reg may be used uninitialized in this function

by checking the return value from read_u8_from_i2c(). This fixes a real problem,
as conf_reg is really uninitialized if read_u8_from_i2c returns an error.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/hwmon/emc2103.c b/drivers/hwmon/emc2103.c
index 9691f664c76e..e7d234b59312 100644
--- a/drivers/hwmon/emc2103.c
+++ b/drivers/hwmon/emc2103.c
@@ -451,11 +451,15 @@ static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da,
                 data->fan_rpm_control = true;
                 break;
         default:
-                mutex_unlock(&data->update_lock);
-                return -EINVAL;
+                count = -EINVAL;
+                goto err;
         }
 
-        read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg);
+        result = read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg);
+        if (result) {
+                count = result;
+                goto err;
+        }
 
         if (data->fan_rpm_control)
                 conf_reg |= 0x80;
@@ -463,7 +467,7 @@ static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da,
                 conf_reg &= ~0x80;
 
         i2c_smbus_write_byte_data(client, REG_FAN_CONF1, conf_reg);
-
+err:
         mutex_unlock(&data->update_lock);
         return count;
 }