i2c: __must_check fixes (chip drivers)

i2c: __must_check fixes (chip drivers)

Check for error on sysfs file creation.
Delete sysfs files on device removal.

The approach taken for the most complex case (pcf8591) is similar to
what Mark M. Hoffman proposed for hardware monitoring chip drivers.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <bgardner@wabtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 19 insertions, 6 deletions

diff --git a/drivers/i2c/chips/max6875.c b/drivers/i2c/chips/max6875.c
index 88d2ddee4490..76645c142977 100644
--- a/drivers/i2c/chips/max6875.c
+++ b/drivers/i2c/chips/max6875.c
@@ -199,8 +199,7 @@ static int max6875_detect(struct i2c_adapter *adapter, int address, int kind)
         mutex_init(&data->update_lock);
 
         /* Init fake client data */
-        /* set the client data to the i2c_client so that it will get freed */
-        i2c_set_clientdata(fake_client, fake_client);
+        i2c_set_clientdata(fake_client, NULL);
         fake_client->addr = address | 1;
         fake_client->adapter = adapter;
         fake_client->driver = &max6875_driver;
@@ -214,13 +213,17 @@ static int max6875_detect(struct i2c_adapter *adapter, int address, int kind)
                 goto exit_kfree2;
 
         if ((err = i2c_attach_client(fake_client)) != 0)
-                goto exit_detach;
+                goto exit_detach1;
 
-        sysfs_create_bin_file(&real_client->dev.kobj, &user_eeprom_attr);
+        err = sysfs_create_bin_file(&real_client->dev.kobj, &user_eeprom_attr);
+        if (err)
+                goto exit_detach2;
 
         return 0;
 
-exit_detach:
+exit_detach2:
+        i2c_detach_client(fake_client);
+exit_detach1:
         i2c_detach_client(real_client);
 exit_kfree2:
         kfree(fake_client);
@@ -229,14 +232,24 @@ exit_kfree1:
         return err;
 }
 
+/* Will be called for both the real client and the fake client */
 static int max6875_detach_client(struct i2c_client *client)
 {
         int err;
+        struct max6875_data *data = i2c_get_clientdata(client);
+
+        /* data is NULL for the fake client */
+        if (data)
+                sysfs_remove_bin_file(&client->dev.kobj, &user_eeprom_attr);
 
         err = i2c_detach_client(client);
         if (err)
                 return err;
-        kfree(i2c_get_clientdata(client));
+
+        if (data)               /* real client */
+                kfree(data);
+        else                    /* fake client */
+                kfree(client);
         return 0;
 }