usb_ep_dequeue(9)
NAME
usb_ep_dequeue - dequeues (cancels, unlinks) an I/O request from an
endpoint
SYNOPSIS
int usb_ep_dequeue(struct usb_ep * ep, struct usb_request * req);
ARGUMENTS
- ep
- the endpoint associated with the request
- req
- the request being canceled
DESCRIPTION
if the request is still active on the endpoint, it is dequeued and its
completion routine is called (with status -ECONNRESET); else a negative
error code is returned.
note that some hardware canīt clear out write fifos (to unlink the
request at the head of the queue) except as part of disconnecting from
usb. such restrictions prevent drivers from supporting configuration
changes, even to configuration zero (a "chapter 9" requirement).
AUTHOR
- David Brownell <dbrownell@users.sourceforge.net>
- Author.