hwmon: (lm75) added error handling

Add error handling so if lm75_update_device fails
an error is returned when reading the value through sysfs.
This is closely modeled after the way this is handled in ltc4261.

Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 1888dd0fc05f..903f22904bf4 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -93,6 +93,10 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 {
         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
         struct lm75_data *data = lm75_update_device(dev);
+
+        if (IS_ERR(data))
+                return PTR_ERR(data);
+
         return sprintf(buf, "%d\n",
                        LM75_TEMP_FROM_REG(data->temp[attr->index]));
 }
@@ -402,6 +406,7 @@ static struct lm75_data *lm75_update_device(struct device *dev)
 {
         struct i2c_client *client = to_i2c_client(dev);
         struct lm75_data *data = i2c_get_clientdata(client);
+        struct lm75_data *ret = data;
 
         mutex_lock(&data->update_lock);
 
@@ -414,19 +419,23 @@ static struct lm75_data *lm75_update_device(struct device *dev)
                         int status;
 
                         status = lm75_read_value(client, LM75_REG_TEMP[i]);
-                        if (status < 0)
-                                dev_dbg(&client->dev, "reg %d, err %d\n",
-                                                LM75_REG_TEMP[i], status);
-                        else
-                                data->temp[i] = status;
+                        if (unlikely(status < 0)) {
+                                dev_dbg(dev,
+                                        "LM75: Failed to read value: reg %d, error %d\n",
+                                        LM75_REG_TEMP[i], status);
+                                ret = ERR_PTR(status);
+                                data->valid = 0;
+                                goto abort;
+                        }
+                        data->temp[i] = status;
                 }
                 data->last_updated = jiffies;
                 data->valid = 1;
         }
 
+abort:
         mutex_unlock(&data->update_lock);
-
-        return data;
+        return ret;
 }
 
 /*-----------------------------------------------------------------------*/