Unfortunately I can't share the source code, it belongs to the company I work for. All of cdev_init, cdev_del, and unregister_chrdev_region are void functions, so they have no return value. I check the return value of alloc_chrdev_region and cdev_add and check for errors with BUG_ON (for now). -Kai Meyer On 10/19/2011 02:18 PM, Daniel Baluta wrote:
On Wed, Oct 19, 2011 at 7:04 PM, Kai Meyer<kai@gnukai.com> wrote:
I can't seem to get my character device to remove itself from the /proc/devices list. I'm calling all of the following functions like so:
alloc_chrdev_region(&dev, 0, 5, "my_char"); cdev_init(&my_cdev,&my_ops); cdev_add(&my_cdev, MKDEV(my_major, my_minor), 1); cdev_del(&my_cdev); unregister_chrdev_region(my_major, 5);
It seems like I'm missing something, but I can't find it. I'm referencing the Linux Device Drivers v3, chapter 3. In the example code, the scull_cleanup_module function calls cdev_dell and unregister_chrdev_region, just like I do.
To be clear, after I unload my module (after calling cdev_del and unregister_chrdev_region), my "my_char" string still shows up in /proc/devices. Did you check return codes for all functions? Also, can you post a link to the code?
thanks, Daniel.
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