Man page 9 : usb_alloc_streams

usb_alloc_streams - allocate bulk endpoint stream IDs.

int usb_alloc_streams(struct usb_interface *  interface , struct usb_host_endpoint **  eps , unsigned int  num_eps , unsigned int  num_streams , gfp_t  mem_flags );

interface
    alternate setting that includes all endpoints.

eps
    array of endpoints that need streams.

num_eps
    number of endpoints in the array.

num_streams
    number of streams to allocate.

mem_flags
    flags hcd should use to allocate memory.

Sets up a group of bulk endpoints to have num_streams stream IDs available. Drivers may queue multiple transfers to different stream IDs, which may complete in a different order than they were queued.