diff mbox series

[06/11] hwmon: (max6650) Simplify alarm handling

Message ID 1556026391-15360-6-git-send-email-linux@roeck-us.net (mailing list archive)
State Changes Requested
Headers show
Series [01/11] hwmon: (max6650) Use devm_add_action to unregister thermal device | expand

Commit Message

Guenter Roeck April 23, 2019, 1:33 p.m. UTC 
Instead of re-reading the alarm register after reporting an alarm,
mark cached values as invalid. While this results in always reading all
data on subsequent reads, it is quite unlikely that such reads will
actually happen before the cache times out. The upside is avoiding
unnecessary unconditional i2c read operations.

Cc: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/max6650.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index cf051f3acf26..c02694d70eee 100644
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -526,15 +526,12 @@  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);
-	struct i2c_client *client = data->client;
-	int alarm = 0;
+	bool alarm = data->alarm & attr->index;
 
-	if (data->alarm & attr->index) {
+	if (alarm) {
 		mutex_lock(&data->update_lock);
-		alarm = 1;
 		data->alarm &= ~attr->index;
-		data->alarm |= i2c_smbus_read_byte_data(client,
-							MAX6650_REG_ALARM);
+		data->valid = false;
 		mutex_unlock(&data->update_lock);
 	}