On Sun, Jul 8, 2012 at 5:33 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Sun, 8 Jul 2012, Kevin Cernekee wrote: > >> usb_gadget_remove_driver() runs through a four-step sequence to shut down >> the gadget driver. For the case of a composite gadget + at91 UDC, this >> would look like: >> >> udc->driver->disconnect(udc->gadget); // composite_disconnect() >> usb_gadget_disconnect(udc->gadget); // at91_pullup(gadget, 0) >> udc->driver->unbind(udc->gadget); // composite_unbind() >> usb_gadget_udc_stop(udc->gadget, udc->driver); // at91_stop() >> >> composite_disconnect() says: >> >> if (cdev->config) >> reset_config(cdev); >> >> reset_config() sets cdev->config to NULL. composite_unbind() later tests >> for this: >> >> WARN_ON(cdev->config); >> >> But SETUP packets may be sent to the composite driver up until the point >> when usb_gadget_disconnect() returns. > > That doesn't sound right. A host can't send SETUP packets to a > disconnected port. The packets should stop arriving when > udc->driver->disconnect returns -- assuming the UDC driver implements > a disconnect method. udc->driver->disconnect points to composite_disconnect(). What is composite_disconnect() doing to tell the UDC driver to disconnect the port from the host? What I see is that usb_gadget_disconnect() does tell the UDC driver to stop activity on the port, but that only happens after composite_disconnect() was called. Can you confirm that the order of the calls in usb_gadget_remove_driver() is correct? Thanks. -- 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
