usb_hcd_check_unlink_urb — check whether an URB may be unlinked
int usb_hcd_check_unlink_urb ( | struct usb_hcd * | hcd, |
| struct urb * | urb, | |
| int | status); |
hcd
host controller to which urb was submitted
urbURB being checked for unlinkability
status
error code to store in urb if the unlink succeeds
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.