Re: [PATCH] hwmon: g762: handle cleanup with devm_add_action

[Guenter Roeck]

On 02/28/2018 07:51 AM, Peng Hao wrote:

Simplify code and use devm_add_action() to handle cleanup.

Signed-off-by: Peng Hao <peng.h...@zte.com.cn>

Excellent idea. Some suggestions for improvements below.

---
  drivers/hwmon/g762.c | 30 ++++++++++++++----------------
  1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/hwmon/g762.c b/drivers/hwmon/g762.c
index 6d1208b..48e60d8 100644
--- a/drivers/hwmon/g762.c
+++ b/drivers/hwmon/g762.c
@@ -128,7 +128,6 @@ enum g762_regs {
                         G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2))

struct g762_data {

-       struct device *hwmon_dev;
        struct i2c_client *client;
        struct clk *clk;

@@ -1051,9 +1050,17 @@ static inline int g762_fan_init(struct device *dev)

                                         data->fan_cmd1);
  }

+static void g762_remove(void *data)

+{
+       struct g762_data *g762 = data;
+       struct i2c_client *client = g762->client;
+
+       g762_of_clock_disable(client);
+}

You could instead just modify the arguments of g762_of_clock_disable()
and call it directly.

  static int g762_probe(struct i2c_client *client, const struct i2c_device_id 
*id)
  {
        struct device *dev = &client->dev;
+       struct device *hwmon_dev;
        struct g762_data *data;
        int ret;

@@ -1086,10 +1093,12 @@ static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)

        if (ret)
                goto clock_dis;

- data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,

-                                                           data, g762_groups);
-       if (IS_ERR(data->hwmon_dev)) {
-               ret = PTR_ERR(data->hwmon_dev);
+       devm_add_action(dev, g762_remove, data);

Move this into g762_of_clock_enable(), just before the return, and the
dummy cleanup function can be dropped. You can then also drop the clock_dis:
label amd instead return immediately on errors.

+
+       hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+                                                          data, g762_groups);
+       if (IS_ERR(hwmon_dev)) {
+               ret = PTR_ERR(hwmon_dev);
                goto clock_dis;

Either case this would now be wrong since the cleanup is handled automatically.
This can be changed to
        return PTR_ERR_OR_ZERO(hwmon_dev);

        }

@@ -1101,23 +1110,12 @@ static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)

        return ret;
  }

-static int g762_remove(struct i2c_client *client)

-{
-       struct g762_data *data = i2c_get_clientdata(client);
-
-       hwmon_device_unregister(data->hwmon_dev);
-       g762_of_clock_disable(client);
-
-       return 0;
-}
-
  static struct i2c_driver g762_driver = {
        .driver = {
                .name = DRVNAME,
                .of_match_table = of_match_ptr(g762_dt_match),
        },
        .probe    = g762_probe,
-       .remove   = g762_remove,
        .id_table = g762_id,
  };