Patchwork macintosh/therm_adt746x: Fix sysfs attributes lifetime

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Submitter Jean Delvare
Date Jan. 31, 2010, 2 p.m.
Message ID <20100131150030.6d83ea5b@hyperion.delvare>
Download mbox | patch
Permalink /patch/44118/
State Accepted
Delegated to: Benjamin Herrenschmidt
Headers show

Comments

Jean Delvare - Jan. 31, 2010, 2 p.m.
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
---
 drivers/macintosh/therm_adt746x.c |   34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

Patch

--- linux-2.6.33-rc3.orig/drivers/macintosh/therm_adt746x.c	2010-01-06 17:30:48.000000000 +0100
+++ linux-2.6.33-rc3/drivers/macintosh/therm_adt746x.c	2010-01-06 17:36:35.000000000 +0100
@@ -90,6 +90,8 @@  static struct task_struct *thread_therm
 
 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 *cli
 	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_c
 		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);