macintosh/therm_adt746x: Fix sysfs attributes lifetime
Jean Delvare [Sun, 31 Jan 2010 04:00:30 +0000 (04:00 +0000)]
Looking at drivers/macintosh/therm_adt746x.c, the sysfs files are
created in thermostat_init() and removed in thermostat_exit(), which
are the driver's init and exit functions. These files are backed-up by
a per-device structure, so it looks like the wrong thing to do: the
sysfs files have a lifetime longer than the data structure that is
backing it up.

I think that sysfs files creation should be moved to the end of
probe_thermostat() and sysfs files removal should be moved to the
beginning of remove_thermostat().

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Colin Leroy <colin@colino.net>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/macintosh/therm_adt746x.c

index 5ff47ba..58809b0 100644 (file)
@@ -90,6 +90,8 @@ static struct task_struct *thread_therm = NULL;
 
 static void write_both_fan_speed(struct thermostat *th, int speed);
 static void write_fan_speed(struct thermostat *th, int speed, int fan);
+static void thermostat_create_files(void);
+static void thermostat_remove_files(void);
 
 static int
 write_reg(struct thermostat* th, int reg, u8 data)
@@ -161,6 +163,8 @@ remove_thermostat(struct i2c_client *client)
        struct thermostat *th = i2c_get_clientdata(client);
        int i;
        
+       thermostat_remove_files();
+
        if (thread_therm != NULL) {
                kthread_stop(thread_therm);
        }
@@ -449,6 +453,8 @@ static int probe_thermostat(struct i2c_client *client,
                return -ENOMEM;
        }
 
+       thermostat_create_files();
+
        return 0;
 }
 
@@ -566,7 +572,6 @@ thermostat_init(void)
        struct device_node* np;
        const u32 *prop;
        int i = 0, offset = 0;
-       int err;
 
        np = of_find_node_by_name(NULL, "fan");
        if (!np)
@@ -633,6 +638,17 @@ thermostat_init(void)
                return -ENODEV;
        }
 
+#ifndef CONFIG_I2C_POWERMAC
+       request_module("i2c-powermac");
+#endif
+
+       return i2c_add_driver(&thermostat_driver);
+}
+
+static void thermostat_create_files(void)
+{
+       int err;
+
        err = device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
        err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
        err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
@@ -647,16 +663,9 @@ thermostat_init(void)
        if (err)
                printk(KERN_WARNING
                        "Failed to create tempertaure attribute file(s).\n");
-
-#ifndef CONFIG_I2C_POWERMAC
-       request_module("i2c-powermac");
-#endif
-
-       return i2c_add_driver(&thermostat_driver);
 }
 
-static void __exit
-thermostat_exit(void)
+static void thermostat_remove_files(void)
 {
        if (of_dev) {
                device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
@@ -673,9 +682,14 @@ thermostat_exit(void)
                        device_remove_file(&of_dev->dev,
                                           &dev_attr_sensor2_fan_speed);
 
-               of_device_unregister(of_dev);
        }
+}
+
+static void __exit
+thermostat_exit(void)
+{
        i2c_del_driver(&thermostat_driver);
+       of_device_unregister(of_dev);
 }
 
 module_init(thermostat_init);