> From: David Brownell <[EMAIL PROTECTED]> > Date: Sat, 20 Oct 2001 19:30:56 -0700
> The simplest answer is (b): > > (b) usb_find_interface_driver() uses the dev->serialize semaphore > for exclusion, but usbdevfs uses the BKL instead. This is not all, it uses driver->serialize() as well. Using only dev->serialize() confuses drivers that expect a single thread in probe(), and they do need a single thread in proble because they need to initialize their mutual exclusion primitives that they might use to serialize other calls. > I think the quick fix would be make usbdevfs use dev->serialize > like find_interface_driver(), and document that as a requrement in > the calling convention for that routine. Possibly. I defer to someone freshly reviewing that. > - usb_drivers_purge() uses driver->serialize while calling > disconnect() > - usb_disconnect() does the same (driver->serialize) > > I don't see how it can be correct to have one set of driver > entries use one lock and the other use a different one, when > they're both affecting the interface bindings. I think it'd be > more correct to use only dev->serialize. driver->serialize is common between probe and disconnect. Using dev->serialize would not work for the reason I pointed out above: driver may attempt to set its globals in probe(). I realize that current Linux has statically initializeable locking primitives which would allow a driver to self-serialize, but I am not sure it would be wise to structure an API around their availability. -- Pete _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
