1 files changed, 685 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c
new file mode 100644
index 000000000000..ba214ebdcd16
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/channel.c
@@ -0,0 +1,685 @@
+/*
+ * Copyright (c) 2014 Qualcomm Atheros, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ath9k.h"
+
+/* Set/change channels.  If the channel is really being changed, it's done
+ * by reseting the chip.  To accomplish this we must first cleanup any pending
+ * DMA, then restart stuff.
+ */
+static int ath_set_channel(struct ath_softc *sc)
+{
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_common *common = ath9k_hw_common(ah);
+	struct ieee80211_hw *hw = sc->hw;
+	struct ath9k_channel *hchan;
+	struct cfg80211_chan_def *chandef = &sc->cur_chan->chandef;
+	struct ieee80211_channel *chan = chandef->chan;
+	int pos = chan->hw_value;
+	int old_pos = -1;
+	int r;
+
+	if (test_bit(ATH_OP_INVALID, &common->op_flags))
+		return -EIO;
+
+	if (ah->curchan)
+		old_pos = ah->curchan - &ah->channels[0];
+
+	ath_dbg(common, CONFIG, "Set channel: %d MHz width: %d\n",
+		chan->center_freq, chandef->width);
+
+	/* update survey stats for the old channel before switching */
+	spin_lock_bh(&common->cc_lock);
+	ath_update_survey_stats(sc);
+	spin_unlock_bh(&common->cc_lock);
+
+	ath9k_cmn_get_channel(hw, ah, chandef);
+
+	/* If the operating channel changes, change the survey in-use flags
+	 * along with it.
+	 * Reset the survey data for the new channel, unless we're switching
+	 * back to the operating channel from an off-channel operation.
+	 */
+	if (!sc->cur_chan->offchannel && sc->cur_survey != &sc->survey[pos]) {
+		if (sc->cur_survey)
+			sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE;
+
+		sc->cur_survey = &sc->survey[pos];
+
+		memset(sc->cur_survey, 0, sizeof(struct survey_info));
+		sc->cur_survey->filled |= SURVEY_INFO_IN_USE;
+	} else if (!(sc->survey[pos].filled & SURVEY_INFO_IN_USE)) {
+		memset(&sc->survey[pos], 0, sizeof(struct survey_info));
+	}
+
+	hchan = &sc->sc_ah->channels[pos];
+	r = ath_reset_internal(sc, hchan);
+	if (r)
+		return r;
+
+	/* The most recent snapshot of channel->noisefloor for the old
+	 * channel is only available after the hardware reset. Copy it to
+	 * the survey stats now.
+	 */
+	if (old_pos >= 0)
+		ath_update_survey_nf(sc, old_pos);
+
+	/* Enable radar pulse detection if on a DFS channel. Spectral
+	 * scanning and radar detection can not be used concurrently.
+	 */
+	if (hw->conf.radar_enabled) {
+		u32 rxfilter;
+
+		/* set HW specific DFS configuration */
+		ath9k_hw_set_radar_params(ah);
+		rxfilter = ath9k_hw_getrxfilter(ah);
+		rxfilter |= ATH9K_RX_FILTER_PHYRADAR |
+				ATH9K_RX_FILTER_PHYERR;
+		ath9k_hw_setrxfilter(ah, rxfilter);
+		ath_dbg(common, DFS, "DFS enabled at freq %d\n",
+			chan->center_freq);
+	} else {
+		/* perform spectral scan if requested. */
+		if (test_bit(ATH_OP_SCANNING, &common->op_flags) &&
+			sc->spectral_mode == SPECTRAL_CHANSCAN)
+			ath9k_spectral_scan_trigger(hw);
+	}
+
+	return 0;
+}
+
+static bool
+ath_chanctx_send_vif_ps_frame(struct ath_softc *sc, struct ath_vif *avp,
+			      bool powersave)
+{
+	struct ieee80211_vif *vif = avp->vif;
+	struct ieee80211_sta *sta = NULL;
+	struct ieee80211_hdr_3addr *nullfunc;
+	struct ath_tx_control txctl;
+	struct sk_buff *skb;
+	int band = sc->cur_chan->chandef.chan->band;
+
+	switch (vif->type) {
+	case NL80211_IFTYPE_STATION:
+		if (!vif->bss_conf.assoc)
+			return false;
+
+		skb = ieee80211_nullfunc_get(sc->hw, vif);
+		if (!skb)
+			return false;
+
+		nullfunc = (struct ieee80211_hdr_3addr *) skb->data;
+		if (powersave)
+			nullfunc->frame_control |=
+				cpu_to_le16(IEEE80211_FCTL_PM);
+
+		skb_set_queue_mapping(skb, IEEE80211_AC_VO);
+		if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, &sta)) {
+			dev_kfree_skb_any(skb);
+			return false;
+		}
+		break;
+	default:
+		return false;
+	}
+
+	memset(&txctl, 0, sizeof(txctl));
+	txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
+	txctl.sta = sta;
+	txctl.force_channel = true;
+	if (ath_tx_start(sc->hw, skb, &txctl)) {
+		ieee80211_free_txskb(sc->hw, skb);
+		return false;
+	}
+
+	return true;
+}
+
+void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx)
+{
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ath_vif *avp;
+	bool active = false;
+	u8 n_active = 0;
+
+	if (!ctx)
+		return;
+
+	list_for_each_entry(avp, &ctx->vifs, list) {
+		struct ieee80211_vif *vif = avp->vif;
+
+		switch (vif->type) {
+		case NL80211_IFTYPE_P2P_CLIENT:
+		case NL80211_IFTYPE_STATION:
+			if (vif->bss_conf.assoc)
+				active = true;
+			break;
+		default:
+			active = true;
+			break;
+		}
+	}
+	ctx->active = active;
+
+	ath_for_each_chanctx(sc, ctx) {
+		if (!ctx->assigned || list_empty(&ctx->vifs))
+			continue;
+		n_active++;
+	}
+
+	if (n_active <= 1) {
+		clear_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags);
+		return;
+	}
+	if (test_and_set_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
+		return;
+	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL);
+}
+
+static bool
+ath_chanctx_send_ps_frame(struct ath_softc *sc, bool powersave)
+{
+	struct ath_vif *avp;
+	bool sent = false;
+
+	rcu_read_lock();
+	list_for_each_entry(avp, &sc->cur_chan->vifs, list) {
+		if (ath_chanctx_send_vif_ps_frame(sc, avp, powersave))
+			sent = true;
+	}
+	rcu_read_unlock();
+
+	return sent;
+}
+
+static bool ath_chanctx_defer_switch(struct ath_softc *sc)
+{
+	if (sc->cur_chan == &sc->offchannel.chan)
+		return false;
+
+	switch (sc->sched.state) {
+	case ATH_CHANCTX_STATE_SWITCH:
+		return false;
+	case ATH_CHANCTX_STATE_IDLE:
+		if (!sc->cur_chan->switch_after_beacon)
+			return false;
+
+		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
+		break;
+	default:
+		break;
+	}
+
+	return true;
+}
+
+static void ath_chanctx_set_next(struct ath_softc *sc, bool force)
+{
+	struct timespec ts;
+	bool measure_time = false;
+	bool send_ps = false;
+
+	spin_lock_bh(&sc->chan_lock);
+	if (!sc->next_chan) {
+		spin_unlock_bh(&sc->chan_lock);
+		return;
+	}
+
+	if (!force && ath_chanctx_defer_switch(sc)) {
+		spin_unlock_bh(&sc->chan_lock);
+		return;
+	}
+
+	if (sc->cur_chan != sc->next_chan) {
+		sc->cur_chan->stopped = true;
+		spin_unlock_bh(&sc->chan_lock);
+
+		if (sc->next_chan == &sc->offchannel.chan) {
+			getrawmonotonic(&ts);
+			measure_time = true;
+		}
+		__ath9k_flush(sc->hw, ~0, true);
+
+		if (ath_chanctx_send_ps_frame(sc, true))
+			__ath9k_flush(sc->hw, BIT(IEEE80211_AC_VO), false);
+
+		send_ps = true;
+		spin_lock_bh(&sc->chan_lock);
+
+		if (sc->cur_chan != &sc->offchannel.chan) {
+			getrawmonotonic(&sc->cur_chan->tsf_ts);
+			sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah);
+		}
+	}
+	sc->cur_chan = sc->next_chan;
+	sc->cur_chan->stopped = false;
+	sc->next_chan = NULL;
+	sc->sched.offchannel_duration = 0;
+	if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE)
+		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
+
+	spin_unlock_bh(&sc->chan_lock);
+
+	if (sc->sc_ah->chip_fullsleep ||
+	    memcmp(&sc->cur_chandef, &sc->cur_chan->chandef,
+		   sizeof(sc->cur_chandef))) {
+		ath_set_channel(sc);
+		if (measure_time)
+			sc->sched.channel_switch_time =
+				ath9k_hw_get_tsf_offset(&ts, NULL);
+	}
+	if (send_ps)
+		ath_chanctx_send_ps_frame(sc, false);
+
+	ath_offchannel_channel_change(sc);
+	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_SWITCH);
+}
+
+void ath_chanctx_work(struct work_struct *work)
+{
+	struct ath_softc *sc = container_of(work, struct ath_softc,
+					    chanctx_work);
+	mutex_lock(&sc->mutex);
+	ath_chanctx_set_next(sc, false);
+	mutex_unlock(&sc->mutex);
+}
+
+void ath_chanctx_init(struct ath_softc *sc)
+{
+	struct ath_chanctx *ctx;
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ieee80211_supported_band *sband;
+	struct ieee80211_channel *chan;
+	int i, j;
+
+	sband = &common->sbands[IEEE80211_BAND_2GHZ];
+	if (!sband->n_channels)
+		sband = &common->sbands[IEEE80211_BAND_5GHZ];
+
+	chan = &sband->channels[0];
+	for (i = 0; i < ATH9K_NUM_CHANCTX; i++) {
+		ctx = &sc->chanctx[i];
+		cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
+		INIT_LIST_HEAD(&ctx->vifs);
+		ctx->txpower = ATH_TXPOWER_MAX;
+		for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
+			INIT_LIST_HEAD(&ctx->acq[j]);
+	}
+	ctx = &sc->offchannel.chan;
+	cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
+	INIT_LIST_HEAD(&ctx->vifs);
+	ctx->txpower = ATH_TXPOWER_MAX;
+	for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
+		INIT_LIST_HEAD(&ctx->acq[j]);
+	sc->offchannel.chan.offchannel = true;
+
+}
+
+void ath9k_chanctx_force_active(struct ieee80211_hw *hw,
+				struct ieee80211_vif *vif)
+{
+	struct ath_softc *sc = hw->priv;
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ath_vif *avp = (struct ath_vif *) vif->drv_priv;
+	bool changed = false;
+
+	if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
+		return;
+
+	if (!avp->chanctx)
+		return;
+
+	mutex_lock(&sc->mutex);
+
+	spin_lock_bh(&sc->chan_lock);
+	if (sc->next_chan || (sc->cur_chan != avp->chanctx)) {
+		sc->next_chan = avp->chanctx;
+		changed = true;
+	}
+	sc->sched.state = ATH_CHANCTX_STATE_FORCE_ACTIVE;
+	spin_unlock_bh(&sc->chan_lock);
+
+	if (changed)
+		ath_chanctx_set_next(sc, true);
+
+	mutex_unlock(&sc->mutex);
+}
+
+void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
+			struct cfg80211_chan_def *chandef)
+{
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+
+	spin_lock_bh(&sc->chan_lock);
+
+	if (test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) &&
+	    (sc->cur_chan != ctx) && (ctx == &sc->offchannel.chan)) {
+		sc->sched.offchannel_pending = true;
+		spin_unlock_bh(&sc->chan_lock);
+		return;
+	}
+
+	sc->next_chan = ctx;
+	if (chandef)
+		ctx->chandef = *chandef;
+
+	if (sc->next_chan == &sc->offchannel.chan) {
+		sc->sched.offchannel_duration =
+			TU_TO_USEC(sc->offchannel.duration) +
+			sc->sched.channel_switch_time;
+	}
+	spin_unlock_bh(&sc->chan_lock);
+	ieee80211_queue_work(sc->hw, &sc->chanctx_work);
+}
+
+void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
+			     struct cfg80211_chan_def *chandef)
+{
+	bool cur_chan;
+
+	spin_lock_bh(&sc->chan_lock);
+	if (chandef)
+		memcpy(&ctx->chandef, chandef, sizeof(*chandef));
+	cur_chan = sc->cur_chan == ctx;
+	spin_unlock_bh(&sc->chan_lock);
+
+	if (!cur_chan)
+		return;
+
+	ath_set_channel(sc);
+}
+
+struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc, bool active)
+{
+	struct ath_chanctx *ctx;
+
+	ath_for_each_chanctx(sc, ctx) {
+		if (!ctx->assigned || list_empty(&ctx->vifs))
+			continue;
+		if (active && !ctx->active)
+			continue;
+
+		if (ctx->switch_after_beacon)
+			return ctx;
+	}
+
+	return &sc->chanctx[0];
+}
+
+void ath_chanctx_offchan_switch(struct ath_softc *sc,
+				struct ieee80211_channel *chan)
+{
+	struct cfg80211_chan_def chandef;
+
+	cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT);
+
+	ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef);
+}
+
+static struct ath_chanctx *
+ath_chanctx_get_next(struct ath_softc *sc, struct ath_chanctx *ctx)
+{
+	int idx = ctx - &sc->chanctx[0];
+
+	return &sc->chanctx[!idx];
+}
+
+static void ath_chanctx_adjust_tbtt_delta(struct ath_softc *sc)
+{
+	struct ath_chanctx *prev, *cur;
+	struct timespec ts;
+	u32 cur_tsf, prev_tsf, beacon_int;
+	s32 offset;
+
+	beacon_int = TU_TO_USEC(sc->cur_chan->beacon.beacon_interval);
+
+	cur = sc->cur_chan;
+	prev = ath_chanctx_get_next(sc, cur);
+
+	getrawmonotonic(&ts);
+	cur_tsf = (u32) cur->tsf_val +
+		  ath9k_hw_get_tsf_offset(&cur->tsf_ts, &ts);
+
+	prev_tsf = prev->last_beacon - (u32) prev->tsf_val + cur_tsf;
+	prev_tsf -= ath9k_hw_get_tsf_offset(&prev->tsf_ts, &ts);
+
+	/* Adjust the TSF time of the AP chanctx to keep its beacons
+	 * at half beacon interval offset relative to the STA chanctx.
+	 */
+	offset = cur_tsf - prev_tsf;
+
+	/* Ignore stale data or spurious timestamps */
+	if (offset < 0 || offset > 3 * beacon_int)
+		return;
+
+	offset = beacon_int / 2 - (offset % beacon_int);
+	prev->tsf_val += offset;
+}
+
+void ath_chanctx_timer(unsigned long data)
+{
+	struct ath_softc *sc = (struct ath_softc *) data;
+
+	ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_TSF_TIMER);
+}
+
+/* Configure the TSF based hardware timer for a channel switch.
+ * Also set up backup software timer, in case the gen timer fails.
+ * This could be caused by a hardware reset.
+ */
+static void ath_chanctx_setup_timer(struct ath_softc *sc, u32 tsf_time)
+{
+	struct ath_hw *ah = sc->sc_ah;
+
+	ath9k_hw_gen_timer_start(ah, sc->p2p_ps_timer, tsf_time, 1000000);
+	tsf_time -= ath9k_hw_gettsf32(ah);
+	tsf_time = msecs_to_jiffies(tsf_time / 1000) + 1;
+	mod_timer(&sc->sched.timer, tsf_time);
+}
+
+void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
+		       enum ath_chanctx_event ev)
+{
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_common *common = ath9k_hw_common(ah);
+	struct ath_beacon_config *cur_conf;
+	struct ath_vif *avp = NULL;
+	struct ath_chanctx *ctx;
+	u32 tsf_time;
+	u32 beacon_int;
+	bool noa_changed = false;
+
+	if (vif)
+		avp = (struct ath_vif *) vif->drv_priv;
+
+	spin_lock_bh(&sc->chan_lock);
+
+	switch (ev) {
+	case ATH_CHANCTX_EVENT_BEACON_PREPARE:
+		if (avp->offchannel_duration)
+			avp->offchannel_duration = 0;
+
+		if (avp->chanctx != sc->cur_chan)
+			break;
+
+		if (sc->sched.offchannel_pending) {
+			sc->sched.offchannel_pending = false;
+			sc->next_chan = &sc->offchannel.chan;
+			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
+		}
+
+		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
+		if (ctx->active && sc->sched.state == ATH_CHANCTX_STATE_IDLE) {
+			sc->next_chan = ctx;
+			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
+		}
+
+		/* if the timer missed its window, use the next interval */
+		if (sc->sched.state == ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
+			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
+
+		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
+			break;
+
+		sc->sched.beacon_pending = true;
+		sc->sched.next_tbtt = REG_READ(ah, AR_NEXT_TBTT_TIMER);
+
+		cur_conf = &sc->cur_chan->beacon;
+		beacon_int = TU_TO_USEC(cur_conf->beacon_interval);
+
+		/* defer channel switch by a quarter beacon interval */
+		tsf_time = sc->sched.next_tbtt + beacon_int / 4;
+		sc->sched.switch_start_time = tsf_time;
+		sc->cur_chan->last_beacon = sc->sched.next_tbtt;
+
+		/* Prevent wrap-around issues */
+		if (avp->periodic_noa_duration &&
+		    tsf_time - avp->periodic_noa_start > BIT(30))
+			avp->periodic_noa_duration = 0;
+
+		if (ctx->active && !avp->periodic_noa_duration) {
+			avp->periodic_noa_start = tsf_time;
+			avp->periodic_noa_duration =
+				TU_TO_USEC(cur_conf->beacon_interval) / 2 -
+				sc->sched.channel_switch_time;
+			noa_changed = true;
+		} else if (!ctx->active && avp->periodic_noa_duration) {
+			avp->periodic_noa_duration = 0;
+			noa_changed = true;
+		}
+
+		/* If at least two consecutive beacons were missed on the STA
+		 * chanctx, stay on the STA channel for one extra beacon period,
+		 * to resync the timer properly.
+		 */
+		if (ctx->active && sc->sched.beacon_miss >= 2)
+			sc->sched.offchannel_duration = 3 * beacon_int / 2;
+
+		if (sc->sched.offchannel_duration) {
+			noa_changed = true;
+			avp->offchannel_start = tsf_time;
+			avp->offchannel_duration =
+				sc->sched.offchannel_duration;
+		}
+
+		if (noa_changed)
+			avp->noa_index++;
+		break;
+	case ATH_CHANCTX_EVENT_BEACON_SENT:
+		if (!sc->sched.beacon_pending)
+			break;
+
+		sc->sched.beacon_pending = false;
+		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
+			break;
+
+		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
+		ath_chanctx_setup_timer(sc, sc->sched.switch_start_time);
+		break;
+	case ATH_CHANCTX_EVENT_TSF_TIMER:
+		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_TIMER)
+			break;
+
+		if (!sc->cur_chan->switch_after_beacon &&
+		    sc->sched.beacon_pending)
+			sc->sched.beacon_miss++;
+
+		sc->sched.state = ATH_CHANCTX_STATE_SWITCH;
+		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
+		break;
+	case ATH_CHANCTX_EVENT_BEACON_RECEIVED:
+		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
+		    sc->cur_chan == &sc->offchannel.chan)
+			break;
+
+		ath_chanctx_adjust_tbtt_delta(sc);
+		sc->sched.beacon_pending = false;
+		sc->sched.beacon_miss = 0;
+
+		/* TSF time might have been updated by the incoming beacon,
+		 * need update the channel switch timer to reflect the change.
+		 */
+		tsf_time = sc->sched.switch_start_time;
+		tsf_time -= (u32) sc->cur_chan->tsf_val +
+			ath9k_hw_get_tsf_offset(&sc->cur_chan->tsf_ts, NULL);
+		tsf_time += ath9k_hw_gettsf32(ah);
+
+
+		ath_chanctx_setup_timer(sc, tsf_time);
+		break;
+	case ATH_CHANCTX_EVENT_ASSOC:
+		if (sc->sched.state != ATH_CHANCTX_STATE_FORCE_ACTIVE ||
+		    avp->chanctx != sc->cur_chan)
+			break;
+
+		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
+		/* fall through */
+	case ATH_CHANCTX_EVENT_SWITCH:
+		if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags) ||
+		    sc->sched.state == ATH_CHANCTX_STATE_FORCE_ACTIVE ||
+		    sc->cur_chan->switch_after_beacon ||
+		    sc->cur_chan == &sc->offchannel.chan)
+			break;
+
+		/* If this is a station chanctx, stay active for a half
+		 * beacon period (minus channel switch time)
+		 */
+		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
+		cur_conf = &sc->cur_chan->beacon;
+
+		sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_TIMER;
+
+		tsf_time = TU_TO_USEC(cur_conf->beacon_interval) / 2;
+		if (sc->sched.beacon_miss >= 2) {
+			sc->sched.beacon_miss = 0;
+			tsf_time *= 3;
+		}
+
+		tsf_time -= sc->sched.channel_switch_time;
+		tsf_time += ath9k_hw_gettsf32(sc->sc_ah);
+		sc->sched.switch_start_time = tsf_time;
+
+		ath_chanctx_setup_timer(sc, tsf_time);
+		sc->sched.beacon_pending = true;
+		break;
+	case ATH_CHANCTX_EVENT_ENABLE_MULTICHANNEL:
+		if (sc->cur_chan == &sc->offchannel.chan ||
+		    sc->cur_chan->switch_after_beacon)
+			break;
+
+		sc->next_chan = ath_chanctx_get_next(sc, sc->cur_chan);
+		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
+		break;
+	case ATH_CHANCTX_EVENT_UNASSIGN:
+		if (sc->cur_chan->assigned) {
+			if (sc->next_chan && !sc->next_chan->assigned &&
+			    sc->next_chan != &sc->offchannel.chan)
+				sc->sched.state = ATH_CHANCTX_STATE_IDLE;
+			break;
+		}
+
+		ctx = ath_chanctx_get_next(sc, sc->cur_chan);
+		sc->sched.state = ATH_CHANCTX_STATE_IDLE;
+		if (!ctx->assigned)
+			break;
+
+		sc->next_chan = ctx;
+		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
+		break;
+	}
+
+	spin_unlock_bh(&sc->chan_lock);
+}