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.

RETURN
       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 4.8.                 January 2017                   USB_HCD_CHECK_UNLINK(9)