hwmon: (jc42) Don't reset hysteresis on device removal

Restoring the configuration register on device removal has the side
effect of also resetting the hysteresis value. This is inconsistent as
the other limits are not reset, only hysteresis. So, following the
principle of least surprise, preserve the hysteresis value when
restoring the configuration register.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c
index 44f189e..e21e43c 100644 (file)
--- a/drivers/hwmon/jc42.c
+++ b/drivers/hwmon/jc42.c
@@ -534,9 +534,16 @@ static int jc42_remove(struct i2c_client *client)
        struct jc42_data *data = i2c_get_clientdata(client);
        hwmon_device_unregister(data->hwmon_dev);
        sysfs_remove_group(&client->dev.kobj, &jc42_group);
-       if (data->config != data->orig_config)
-               i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
-                                            data->orig_config);
+
+       /* Restore original configuration except hysteresis */
+       if ((data->config & ~JC42_CFG_HYST_MASK) !=
+           (data->orig_config & ~JC42_CFG_HYST_MASK)) {
+               int config;
+
+               config = (data->orig_config & ~JC42_CFG_HYST_MASK)
+                 | (data->config & JC42_CFG_HYST_MASK);
+               i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
+       }
        return 0;
 }