Man page 9 : usb_hcd_link_urb_to_ep

usb_hcd_link_urb_to_ep - add an URB to its endpoint queue

int usb_hcd_link_urb_to_ep(struct usb_hcd *  hcd , struct urb *  urb );

hcd
    host controller to which urb was submitted

urb
    URB being submitted

Host controller drivers should call this routine in their enqueue method. The HCDAqs private spinlock must be held and interrupts must be disabled. The actions carried out here are required for URB submission, as well as for endpoint shutdown and for usb_kill_urb.

Returns 0 for no error, otherwise a negative error code (in which case the enqueue method must fail). If no error occurs but enqueue fails anyway, it must call usb_hcd_unlink_urb_from_ep before releasing the private spinlock and returning.