> > + /* For reasons that have been lost in antiquity, the TTY > > layer calls > > + * our close method even if the open call fails. Hence we > > must not > > + * drop the reference obtained by usb_serial_get_by_index(). Not lost in antiquity: The logic is this open do some opening work block on carrier HANGUP open returns error cleanup still required So the tty layer always went that way so that the awkward cases around an opening failing with a hangup just go away. For the normal drivers which basically do open: tty layer open work open hardware and set ASYNCB_INITIALIZED block for carrier close: if (!hung_up) { if initialized shutdown() } the USB layer works really hard to be completely different (in part because the old code simply didn't implement open semantics properly or hangup correctly - hence things like mgetty fail on them). The later patches I was working on were trying to get USB serial to the point where the model was that drv->open/drv->close were the hardware init/shutdown and did indeed get called in nice matching open/close pairs and not re-entered or called unserialized. Nice spot on the ASYNC v ASYNCB bug Alan btw Alan (the other one) -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html