On Wed, 16 Mar 2005 [EMAIL PROTECTED] wrote: > The problem is not reference counting the problem is some code in > driver/base/bus.c. First I will describe the scenario:
> All is well and we call the driver remove function which calls > acm_disconnect. acm_disconnect calls usb_driver_release_interface > with the other interface which re-enters device_release_driver > and removes its entry from the list. Unfortunately this call > detaches driver_detach's next pointer from the > list it is iterating over so when we return from the outside call > of device_release_driver next->next is itself and will never be > equal to the list head which is list_for_each_safe's loop end > condition. This is very bad. > > I don't really understand why this is such an unusual situation > but it results from us freeing the interfaces in a different order > to that we claim them in - shouldn't the device driver interface > handle this - at least without an infinite loop? > > As far as I can see device_release_driver should *never* be called > from somewhere which is called from device_release_driver with > the current implimentation and I really can't understand that this has > never happened before... This is exactly the sort of thing that would be cured by removing the subsystem rwsem and changing the internal operation of the driver-model core. Another problem that would be solved is adding/deleting devices during a probe(), remove(), or resume() callback. Greg, I've got some pretty good ideas about how to do it. But they're not fully developed and I need help settling some issues. What's a good mailing list to discuss these things on? LKML? Alan Stern ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
