Re: MOD_INC_USE_COUNT

[Ralf Baechle <ralf@linux-mips.org>]

On Tue, Nov 15, 2005 at 11:56:33AM +0800, Tony wrote:

> >Not strange at all.  The typical network driver is implemented using
> >pci_register_driver which will set the owner filed of the driver's struct
> >driver which then is being used for internal reference counting.  Other
> >busses or line disciplines (SLIP, PPP, AX.25 ...) need to do the equivalent
> >or the kernel will believe reference counting isn't necessary and it's
> >ok to unload the module at any time.
> >
> >In which driver did you hit this problem?
> >
> >  Ralf
> >
> I have a radio connected to host using ethernet. I'm writing a radio 
> driver that masquerade radio as a NIC. when the module is loaded, I just 
> register_netdev a net_device struct, while unregister_netdev at module 
> cleanup.

register_netdev / unregister_netdev don't deal with the .owner stuff, so
your bug isn't there.  If your NIC is a PCI card, it should register it's
driver through pci_register_driver which would deal with the necessary
reference counting.  If it's implemented as a platform device you're
presumably calling driver_register() before platform_device_register() and
driver_register() would do the necessary magic for you.  If you're using a
different bus it may have it's own variant of driver_register which you
should call.  If you don't, you have a problem :-)

  Ralf