Linux-libre 4.4-gnupck-4.4-gnu

1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index 65482624e..5289aa098 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -58,6 +58,7 @@ struct tmp102 {
 	u16 config_orig;
 	unsigned long last_update;
 	int temp[3];
+	bool first_time;
 };
 
 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
@@ -93,6 +94,7 @@ static struct tmp102 *tmp102_update_device(struct device *dev)
 				tmp102->temp[i] = tmp102_reg_to_mC(status);
 		}
 		tmp102->last_update = jiffies;
+		tmp102->first_time = false;
 	}
 	mutex_unlock(&tmp102->lock);
 	return tmp102;
@@ -102,6 +104,12 @@ static int tmp102_read_temp(void *dev, int *temp)
 {
 	struct tmp102 *tmp102 = tmp102_update_device(dev);
 
+	/* Is it too early even to return a conversion? */
+	if (tmp102->first_time) {
+		dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
+		return -EAGAIN;
+	}
+
 	*temp = tmp102->temp[0];
 
 	return 0;
@@ -114,6 +122,10 @@ static ssize_t tmp102_show_temp(struct device *dev,
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct tmp102 *tmp102 = tmp102_update_device(dev);
 
+	/* Is it too early even to return a read? */
+	if (tmp102->first_time)
+		return -EAGAIN;
+
 	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
 }
 
@@ -207,7 +219,9 @@ static int tmp102_probe(struct i2c_client *client,
 		status = -ENODEV;
 		goto fail_restore_config;
 	}
-	tmp102->last_update = jiffies - HZ;
+	tmp102->last_update = jiffies;
+	/* Mark that we are not ready with data until conversion is complete */
+	tmp102->first_time = true;
 	mutex_init(&tmp102->lock);
 
 	hwmon_dev = hwmon_device_register_with_groups(dev, client->name,