hwmon: (max6650) Improve error handling in max6650_update_device

Pass errors from i2c_smbus_read_byte_data() back to the caller of
max6650_update_device().

Cc: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 6f1a1a6eae46844f6dd3b4b895a56f6bfc9cf6f4..e65792020ca1ec84ab50755cedd1986e9dd5f828 100644 (file)
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -157,14 +157,19 @@ static struct max6650_data *max6650_update_device(struct device *dev)
 {
        struct max6650_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
+       int reg, err = 0;
        int i;
 
        mutex_lock(&data->update_lock);
 
        if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
                for (i = 0; i < data->nr_fans; i++) {
-                       data->tach[i] = i2c_smbus_read_byte_data(client,
-                                                                tach_reg[i]);
+                       reg = i2c_smbus_read_byte_data(client, tach_reg[i]);
+                       if (reg < 0) {
+                               err = reg;
+                               goto error;
+                       }
+                       data->tach[i] = reg;
                }
 
                /*
@@ -172,15 +177,20 @@ static struct max6650_data *max6650_update_device(struct device *dev)
                 * caused the alarm is removed. Keep the value latched here
                 * for providing the register through different alarm files.
                 */
-               data->alarm |= i2c_smbus_read_byte_data(client,
-                                                       MAX6650_REG_ALARM);
-
+               reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM);
+               if (reg < 0) {
+                       err = reg;
+                       goto error;
+               }
+               data->alarm |= reg;
                data->last_updated = jiffies;
                data->valid = true;
        }
 
+error:
        mutex_unlock(&data->update_lock);
-
+       if (err)
+               data = ERR_PTR(err);
        return data;
 }
 
@@ -289,8 +299,12 @@ static ssize_t alarm_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct max6650_data *data = max6650_update_device(dev);
-       bool alarm = data->alarm & attr->index;
+       bool alarm;
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       alarm = data->alarm & attr->index;
        if (alarm) {
                mutex_lock(&data->update_lock);
                data->alarm &= ~attr->index;
@@ -512,6 +526,9 @@ static int max6650_read(struct device *dev, enum hwmon_sensor_types type,
        struct max6650_data *data = max6650_update_device(dev);
        int mode;
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        switch (type) {
        case hwmon_pwm:
                switch (attr) {