Re: [PATCH]drivers/char/cs5535_gpio.c:call cdev_del during module_exit to unmap kobject references and other cleanups.

["Thayumanavar Sachithanantham" <thayumk@gmail.com>]

During module unloading, cdev_del be called to unmap cdev related
kobject references and other cleanups(such as inode->i_cdev being set
to NULL) which prevents the OOPS upon subsequent loading ,usage and
unloading of modules(as seen in the mail thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=114533640609018&w=2).

Removed test of gpio_base as it is unneeded and will not be zero at
module unload time.

Signed-off-by: Thayumanavar Sachithanantham <thayumk@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

--- linux-2.6/drivers/char/cs5535_gpio.c.orig	2006-04-17
21:37:25.000000000 -0700
+++ linux-2.6/drivers/char/cs5535_gpio.c	2006-04-17 23:05:49.000000000 -0700
@@ -241,9 +241,9 @@ static int __init cs5535_gpio_init(void)
 static void __exit cs5535_gpio_cleanup(void)
 {
 	dev_t dev_id = MKDEV(major, 0);
+        cdev_del(&cs5535_gpio_cdev);
 	unregister_chrdev_region(dev_id, CS5535_GPIO_COUNT);
-	if (gpio_base != 0)
-		release_region(gpio_base, CS5535_GPIO_SIZE);
+	release_region(gpio_base, CS5535_GPIO_SIZE);
 }

 module_init(cs5535_gpio_init);