Thank you very much for your help.
returning "0 on Success" instead of "the positive, non-zero deviceMajorNum on Success" in the hostQueryModuleInit function seems to fix the problem.
I can now do insmod, rmmod. I have tried it many times and it works.
Thanks
Vijay
Daniele Bellucci wrote:
> In function:
>
> int
> hostQueryModuleInit
> (
> void
> )
> {
> if (!pci_present ())
> {
> printk
> (
> KERN_WARNING "%s.%d::No pci... Aborting.\n",
> __FILE__,
> __LINE__
> );
> return -1;
> }
>
> printk
> (
> KERN_INFO "After pci_present\n"
> );
>
> // ... Get dynamic major number from kernel
> queryMajorNum = register_chrdev (0, "queryd", &queryDevice_fops);
>
> printk
> (
> KERN_INFO "After register_chrdev\n"
> );
>
> if (queryMajorNum < 0)
> {
> printk
> (
> KERN_ERR "%s.%d::register_chrdev(%s) returned (%d)...\n",
> __FILE__,
> __LINE__,
> "queryd",
> queryMajorNum
> );
>
> return queryMajorNum;
> }
>
> queryDevRegistered = 1;
>
> //hostQueryRegisterSymbols ();
>
> printk
> (
> KERN_INFO "After hostQueryRegisterSymbols:%u \n",
> queryMajorNum
> );
>
> /*WRONG!!!*/ return queryMajorNum;
> /*MUST BE: return 0;
> }
>
> If register_chrdev success you don't need to return queryMajorNum,
> as a general rule:
> if a module intialization function you need to return 0 if everything success, !=0 if fail.
>
> You module is wrong because you register a chrdev, and this success... but because of
> your module_init return !=0 init_module fails without releasing resources allocated.
>
> Hope this help.
>
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