On Thursday 08 June 2006 8:26 pm, Alan Stern wrote: > On Thu, 8 Jun 2006, David Brownell wrote: > > > That said, I don't see an obvious race there. If the device disconnects, > > there's now a guarantee that all pending urbs will have completed before > > the driver disconnect() method is called. (As of maybe 2.6.8 or so. The > > original 2.4 code of course couldn't rely on such guarantees. The lack of > > such guarantees meant a seemingly endless supply of oops-on-disconnect > > bugs.) > > But there's no guarantee that URBs submitted _after_ the disconnect method > has returned will fail.
Yes there is ... they fail during submit, since the device is marked as gone. Submits start failing even before disconnect() is called. > (Of course, if the device really has been > unplugged then they definitely will fail, but if the driver has merely > been unbound from the interface then they might not.) Drivers do need to > have sufficient synchronization to avoid this problem. Well, the specific scenario here was errors on unplug, not rmmod; and I'd call it an error if URBs could be submitted to endpoints that aren't bound to some driver. (Yep, likely we have bugs in that space.) - Dave _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
