Trouble removing character device

[Kai Meyer]

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 at 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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