usb_hcd_check_unlink(9)
NAME
usb_hcd_check_unlink_urb - check whether an URB may be unlinked
SYNOPSIS
int usb_hcd_check_unlink_urb(struct usb_hcd * hcd, struct urb * urb,
int status);
ARGUMENTS
- hcd
- host controller to which urb was submitted
- urb
- URB being checked for unlinkability
- status
- error code to store in urb if the unlink succeeds
DESCRIPTION
Host controller drivers should call this routine in their dequeue
method. The HCD´s private spinlock must be held and interrupts must be
disabled. The actions carried out here are required for making sure
than an unlink is valid.
Returns 0 for no error, otherwise a negative error code (in which case the dequeue method must fail). The possible error codes are:
-EIDRM: urb was not submitted or has already completed. The completion
function may not have been called yet.
-EBUSY: urb has already been unlinked.