[PATCH 06/20] hwmon: (tmp421) Rely on subsystem locking

[Guenter Roeck <linux@roeck-us.net>]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/tmp421.c | 21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
index 9537727aad9a..2e43ce8408d6 100644
--- a/drivers/hwmon/tmp421.c
+++ b/drivers/hwmon/tmp421.c
@@ -19,7 +19,6 @@
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/sysfs.h>
 
@@ -99,7 +98,6 @@ struct tmp421_channel {
 
 struct tmp421_data {
 	struct i2c_client *client;
-	struct mutex update_lock;
 	u32 temp_config[MAX_CHANNELS + 1];
 	struct hwmon_channel_info temp_info;
 	const struct hwmon_channel_info *info[2];
@@ -130,38 +128,28 @@ static int tmp421_update_device(struct tmp421_data *data)
 	int ret = 0;
 	int i;
 
-	mutex_lock(&data->update_lock);
-
 	if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
 	    !data->valid) {
+		data->valid = false;
 		ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
 		if (ret < 0)
-			goto exit;
+			return ret;
 		data->config = ret;
 
 		for (i = 0; i < data->channels; i++) {
 			ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
 			if (ret < 0)
-				goto exit;
+				return ret;
 			data->channel[i].temp = ret << 8;
 
 			ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
 			if (ret < 0)
-				goto exit;
+				return ret;
 			data->channel[i].temp |= ret;
 		}
 		data->last_updated = jiffies;
 		data->valid = true;
 	}
-
-exit:
-	mutex_unlock(&data->update_lock);
-
-	if (ret < 0) {
-		data->valid = false;
-		return ret;
-	}
-
 	return 0;
 }
 
@@ -442,7 +430,6 @@ static int tmp421_probe(struct i2c_client *client)
 	if (!data)
 		return -ENOMEM;
 
-	mutex_init(&data->update_lock);
 	data->channels = (unsigned long)i2c_get_match_data(client);
 	data->client = client;
 
-- 
2.45.2