Function scan_start

freebsd/net80211/ieee80211_scan_sw.c:619–674

}

static void
scan_start(void *arg, int pending)
{
#define	ISCAN_REP	(ISCAN_MINDWELL | ISCAN_DISCARD)
	struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
	struct scan_state *ss_priv = SCAN_PRIVATE(ss);
	struct ieee80211vap *vap = ss->ss_vap;
	struct ieee80211com *ic = ss->ss_ic;

	IEEE80211_LOCK(ic);
	if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
	    (ss_priv->ss_iflags & ISCAN_ABORT)) {
		/* Cancelled before we started */
		scan_done(ss, 0);
		return;
	}

	if (ss->ss_next == ss->ss_last) {
		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
			"%s: no channels to scan\n", __func__);
		scan_done(ss, 1);
		return;
	}

	/*
	 * Put the station into power save mode.
	 *
	 * This is only required if we're not a full-offload devices;
	 * those devices manage scan/traffic differently.
	 */
	if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) &&
	    vap->iv_opmode == IEEE80211_M_STA &&
	    vap->iv_state == IEEE80211_S_RUN) {
		if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
			/* Enable station power save mode */
			vap->iv_sta_ps(vap, 1);
			/* Wait until null data frame will be ACK'ed */
			mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH,
			    "sta_ps", msecs_to_ticks(10));
			if (ss_priv->ss_iflags & ISCAN_ABORT) {
				scan_done(ss, 0);
				return;
			}
		}
	}

	ss_priv->ss_scanend = ticks + ss_priv->ss_duration;

	/* XXX scan state can change! Re-validate scan state! */

	IEEE80211_UNLOCK(ic);

	ic->ic_scan_start(ic);		/* notify driver */

	scan_curchan_task(ss, 0);
}

static void