Comments on: register the driver acording to 2.4 kernal give error in rmmod and all hedar file and decleartion are include in heder24.h https://www.emblogic.com/blog/09/register-the-driver-acording-to-2-4-kernal-give-error-in-rmmod-and-all-hedar-file-and-decleartion-are-include-in-heder24-h/ Embedded System and ARM Training Mon, 07 Oct 2013 04:00:03 +0000 hourly 1 http://wordpress.org/?v=3.9.1 By: kamran https://www.emblogic.com/blog/09/register-the-driver-acording-to-2-4-kernal-give-error-in-rmmod-and-all-hedar-file-and-decleartion-are-include-in-heder24-h/#comment-285 Sun, 02 Oct 2011 19:34:36 +0000 http://emblogic.org/blog/?p=885#comment-285 int register_chrdev (unsigned int major,const char *name,const struct file_operations *fops);
the return value is saved in retvl it has to be UNSIGNED INT retvl instead of int.

Since you are passing the retvl as the first argument in unregister_chrdev, WHICH IS UNSIGNED again.
int unregister_chrdev(unsigned int major, const char *name);

Plus you can add the following lines to check the unregister_chrdev .

ret = unregister_chrdev(retvl, DEVICE_NAME);
if (ret < 0) printk("Error in unregister_chrdev: %d\n", ret);

This is help out in atleast understanding the problem encountered during unregister_chrdev the device.

]]> By: Kuldeep Dhanotia https://www.emblogic.com/blog/09/register-the-driver-acording-to-2-4-kernal-give-error-in-rmmod-and-all-hedar-file-and-decleartion-are-include-in-heder24-h/#comment-273 Sat, 01 Oct 2011 13:23:33 +0000 http://emblogic.org/blog/?p=885#comment-273 i thought we should include 2.4 level headers

]]> By: Vaibhav Singh https://www.emblogic.com/blog/09/register-the-driver-acording-to-2-4-kernal-give-error-in-rmmod-and-all-hedar-file-and-decleartion-are-include-in-heder24-h/#comment-260 Fri, 30 Sep 2011 10:51:57 +0000 http://emblogic.org/blog/?p=885#comment-260 Blog the errors also……..

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