ra_work
struct ra_work *ra_work = (struct ra_work *)wk;
struct mscp *mp = &ra_work->ra_mw.mw_mp;
device_t usc = ra_work->ra_usc;
struct ra_work ra_work;/* online callback handling */
ra->ra_work.ra_usc = usc;
ra->ra_work.ra_mw.mw_mi = mi;
ra->ra_work.ra_mw.mw_mp = *mp;
ra->ra_work.ra_mw.mw_online = true;
workqueue_enqueue(mi->mi_wq, (struct work *)&ra->ra_work, NULL);