hwmon: Fix a potential race condition on unload

Fix a potential race condition when some hardware monitoring platform
drivers are being unloaded. I believe that the driver data pointer
shouldn't be cleared before all the sysfs files are removed, otherwise
a sysfs callback might attempt to dereference a NULL pointer. I'm not
sure exactly what the driver core protects drivers against, so let's
play it safe.

While we're here, clear the driver data pointer when probe fails, so
as to not leave an invalid pointer behind us.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c
index e8b15047a6d3..8fe4d70d8f51 100644
--- a/drivers/hwmon/f71805f.c
+++ b/drivers/hwmon/f71805f.c
@@ -1242,12 +1242,12 @@ static int __devexit f71805f_remove(struct platform_device *pdev)
         struct resource *res;
         int i;
 
-        platform_set_drvdata(pdev, NULL);
         hwmon_device_unregister(data->class_dev);
         sysfs_remove_group(&pdev->dev.kobj, &f71805f_group);
         for (i = 0; i < 4; i++)
                 sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_optin[i]);
         sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_pwm_freq);
+        platform_set_drvdata(pdev, NULL);
         kfree(data);
 
         res = platform_get_resource(pdev, IORESOURCE_IO, 0);