suse man page for usb_hcd_check_unlink_urb

USB_HCD_CHECK_UNLINK(9) 				       Host Controller APIs					   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.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						   USB_HCD_CHECK_UNLINK(9)