From 5b8206fb91b97732d80ada2e494e060d50ab30bd Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Tue, 29 Nov 2011 10:20:02 +0100
Subject: [PATCH 080/130] mac80211: revert on-channel work optimisations

commit e76aadc572288a158ae18ae1c10fe395c7bca066 upstream.

Backport note:
This patch it's a full revert of commit b23b025f "mac80211: Optimize
scans on current operating channel.". On upstrem revert e76aadc5 we
keep some bits from that commit, which are needed for upstream version
of mac80211.

The on-channel work optimisations have caused a
number of issues, and the code is unfortunately
very complex and almost impossible to follow.
Instead of attempting to put in more workarounds
let's just remove those optimisations, we can
work on them again later, after we change the
whole auth/assoc design.

This should fix rate_control_send_low() warnings,
see RH bug 731365.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 net/mac80211/ieee80211_i.h |   13 +++----
 net/mac80211/main.c        |   58 +++-----------------------------
 net/mac80211/offchannel.c  |   68 +++++++++++++++++---------------------
 net/mac80211/rx.c          |   10 ++++-
 net/mac80211/scan.c        |   77 ++++++++++++-------------------------------
 net/mac80211/tx.c          |    3 +-
 net/mac80211/work.c        |   77 ++++++-------------------------------------
 7 files changed, 85 insertions(+), 221 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ea10a51..73495f1 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -702,6 +702,8 @@ struct tpt_led_trigger {
  *	well be on the operating channel
  * @SCAN_HW_SCANNING: The hardware is scanning for us, we have no way to
  *	determine if we are on the operating channel or not
+ * @SCAN_OFF_CHANNEL: We're off our operating channel for scanning,
+ *	gets only set in conjunction with SCAN_SW_SCANNING
  * @SCAN_COMPLETED: Set for our scan work function when the driver reported
  *	that the scan completed.
  * @SCAN_ABORTED: Set for our scan work function when the driver reported
@@ -710,6 +712,7 @@ struct tpt_led_trigger {
 enum {
 	SCAN_SW_SCANNING,
 	SCAN_HW_SCANNING,
+	SCAN_OFF_CHANNEL,
 	SCAN_COMPLETED,
 	SCAN_ABORTED,
 };
@@ -1140,14 +1143,10 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata);
 void ieee80211_sched_scan_stopped_work(struct work_struct *work);
 
 /* off-channel helpers */
-bool ieee80211_cfg_on_oper_channel(struct ieee80211_local *local);
-void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
-					bool tell_ap);
-void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
-				    bool offchannel_ps_enable);
+void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local);
+void ieee80211_offchannel_stop_station(struct ieee80211_local *local);
 void ieee80211_offchannel_return(struct ieee80211_local *local,
-				 bool enable_beaconing,
-				 bool offchannel_ps_disable);
+				 bool enable_beaconing);
 void ieee80211_hw_roc_setup(struct ieee80211_local *local);
 
 /* interface handling */
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index cae4435..a7536fd 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -92,47 +92,6 @@ static void ieee80211_reconfig_filter(struct work_struct *work)
 	ieee80211_configure_filter(local);
 }
 
-/*
- * Returns true if we are logically configured to be on
- * the operating channel AND the hardware-conf is currently
- * configured on the operating channel.  Compares channel-type
- * as well.
- */
-bool ieee80211_cfg_on_oper_channel(struct ieee80211_local *local)
-{
-	struct ieee80211_channel *chan, *scan_chan;
-	enum nl80211_channel_type channel_type;
-
-	/* This logic needs to match logic in ieee80211_hw_config */
-	if (local->scan_channel) {
-		chan = local->scan_channel;
-		/* If scanning on oper channel, use whatever channel-type
-		 * is currently in use.
-		 */
-		if (chan == local->oper_channel)
-			channel_type = local->_oper_channel_type;
-		else
-			channel_type = NL80211_CHAN_NO_HT;
-	} else if (local->tmp_channel) {
-		chan = scan_chan = local->tmp_channel;
-		channel_type = local->tmp_channel_type;
-	} else {
-		chan = local->oper_channel;
-		channel_type = local->_oper_channel_type;
-	}
-
-	if (chan != local->oper_channel ||
-	    channel_type != local->_oper_channel_type)
-		return false;
-
-	/* Check current hardware-config against oper_channel. */
-	if ((local->oper_channel != local->hw.conf.channel) ||
-	    (local->_oper_channel_type != local->hw.conf.channel_type))
-		return false;
-
-	return true;
-}
-
 int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 {
 	struct ieee80211_channel *chan, *scan_chan;
@@ -145,9 +104,6 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 
 	scan_chan = local->scan_channel;
 
-	/* If this off-channel logic ever changes,  ieee80211_on_oper_channel
-	 * may need to change as well.
-	 */
 	offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
 	if (scan_chan) {
 		chan = scan_chan;
@@ -158,19 +114,17 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
 			channel_type = local->_oper_channel_type;
 		else
 			channel_type = NL80211_CHAN_NO_HT;
-	} else if (local->tmp_channel) {
+		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
+	} else if (local->tmp_channel &&
+		   local->oper_channel != local->tmp_channel) {
 		chan = scan_chan = local->tmp_channel;
 		channel_type = local->tmp_channel_type;
+		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
 	} else {
 		chan = local->oper_channel;
 		channel_type = local->_oper_channel_type;
-	}
-
-	if (chan != local->oper_channel ||
-	    channel_type != local->_oper_channel_type)
-		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
-	else
 		local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
+	}
 
 	offchannel_flag ^= local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
 
@@ -279,7 +233,7 @@ void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
 
 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
 		if (local->quiescing || !ieee80211_sdata_running(sdata) ||
-		    test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) {
+		    test_bit(SCAN_SW_SCANNING, &local->scanning)) {
 			sdata->vif.bss_conf.enable_beacon = false;
 		} else {
 			/*
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 3d41441..1b239be 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -18,14 +18,10 @@
 #include "driver-trace.h"
 
 /*
- * Tell our hardware to disable PS.
- * Optionally inform AP that we will go to sleep so that it will buffer
- * the frames while we are doing off-channel work.  This is optional
- * because we *may* be doing work on-operating channel, and want our
- * hardware unconditionally awake, but still let the AP send us normal frames.
+ * inform AP that we will go to sleep so that it will buffer the frames
+ * while we scan
  */
-static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
-					   bool tell_ap)
+static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
@@ -46,8 +42,8 @@ static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 	}
 
-	if (tell_ap && (!local->offchannel_ps_enabled ||
-			!(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)))
+	if (!(local->offchannel_ps_enabled) ||
+	    !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
 		/*
 		 * If power save was enabled, no need to send a nullfunc
 		 * frame because AP knows that we are sleeping. But if the
@@ -82,9 +78,6 @@ static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
 		 * we are sleeping, let's just enable power save mode in
 		 * hardware.
 		 */
-		/* TODO:  Only set hardware if CONF_PS changed?
-		 * TODO:  Should we set offchannel_ps_enabled to false?
-		 */
 		local->hw.conf.flags |= IEEE80211_CONF_PS;
 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
@@ -103,61 +96,63 @@ static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
 	ieee80211_sta_reset_conn_monitor(sdata);
 }
 
-void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
-				    bool offchannel_ps_enable)
+void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
 {
 	struct ieee80211_sub_if_data *sdata;
 
-	/*
-	 * notify the AP about us leaving the channel and stop all
-	 * STA interfaces.
-	 */
 	mutex_lock(&local->iflist_mtx);
 	list_for_each_entry(sdata, &local->interfaces, list) {
 		if (!ieee80211_sdata_running(sdata))
 			continue;
 
-		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
-			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
-
-		/* Check to see if we should disable beaconing. */
+		/* disable beaconing */
 		if (sdata->vif.type == NL80211_IFTYPE_AP ||
 		    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
 		    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 			ieee80211_bss_info_change_notify(
 				sdata, BSS_CHANGED_BEACON_ENABLED);
 
-		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
+		/*
+		 * only handle non-STA interfaces here, STA interfaces
+		 * are handled in ieee80211_offchannel_stop_station(),
+		 * e.g., from the background scan state machine.
+		 *
+		 * In addition, do not stop monitor interface to allow it to be
+		 * used from user space controlled off-channel operations.
+		 */
+		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+		    sdata->vif.type != NL80211_IFTYPE_MONITOR) {
+			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
 			netif_tx_stop_all_queues(sdata->dev);
-			if (offchannel_ps_enable &&
-			    (sdata->vif.type == NL80211_IFTYPE_STATION) &&
-			    sdata->u.mgd.associated)
-				ieee80211_offchannel_ps_enable(sdata, true);
 		}
 	}
 	mutex_unlock(&local->iflist_mtx);
 }
 
-void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
-					bool tell_ap)
+void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
 {
 	struct ieee80211_sub_if_data *sdata;
 
+	/*
+	 * notify the AP about us leaving the channel and stop all STA interfaces
+	 */
 	mutex_lock(&local->iflist_mtx);
 	list_for_each_entry(sdata, &local->interfaces, list) {
 		if (!ieee80211_sdata_running(sdata))
 			continue;
 
-		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
-		    sdata->u.mgd.associated)
-			ieee80211_offchannel_ps_enable(sdata, tell_ap);
+		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
+			netif_tx_stop_all_queues(sdata->dev);
+			if (sdata->u.mgd.associated)
+				ieee80211_offchannel_ps_enable(sdata);
+		}
 	}
 	mutex_unlock(&local->iflist_mtx);
 }
 
 void ieee80211_offchannel_return(struct ieee80211_local *local,
-				 bool enable_beaconing,
-				 bool offchannel_ps_disable)
+				 bool enable_beaconing)
 {
 	struct ieee80211_sub_if_data *sdata;
 
@@ -167,8 +162,7 @@ void ieee80211_offchannel_return(struct ieee80211_local *local,
 			continue;
 
 		/* Tell AP we're back */
-		if (offchannel_ps_disable &&
-		    sdata->vif.type == NL80211_IFTYPE_STATION) {
+		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 			if (sdata->u.mgd.associated)
 				ieee80211_offchannel_ps_disable(sdata);
 		}
@@ -188,7 +182,7 @@ void ieee80211_offchannel_return(struct ieee80211_local *local,
 			netif_tx_wake_all_queues(sdata->dev);
 		}
 
-		/* Check to see if we should re-enable beaconing */
+		/* re-enable beaconing */
 		if (enable_beaconing &&
 		    (sdata->vif.type == NL80211_IFTYPE_AP ||
 		     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index fb123e2..5c51607 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -421,10 +421,16 @@ ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 		return RX_CONTINUE;
 
 	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-	    test_bit(SCAN_SW_SCANNING, &local->scanning) ||
 	    local->sched_scanning)
 		return ieee80211_scan_rx(rx->sdata, skb);
 
+	if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
+		/* drop all the other packets during a software scan anyway */
+		if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
+			dev_kfree_skb(skb);
+		return RX_QUEUED;
+	}
+
 	/* scanning finished during invoking of handlers */
 	I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 	return RX_DROP_UNUSABLE;
@@ -2858,7 +2864,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 		local->dot11ReceivedFragmentCount++;
 
 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-		     test_bit(SCAN_SW_SCANNING, &local->scanning)))
+		     test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
 		status->rx_flags |= IEEE80211_RX_IN_SCAN;
 
 	if (ieee80211_is_mgmt(fc))
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 105436d..5279300 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -213,14 +213,6 @@ ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 	if (bss)
 		ieee80211_rx_bss_put(sdata->local, bss);
 
-	/* If we are on-operating-channel, and this packet is for the
-	 * current channel, pass the pkt on up the stack so that
-	 * the rest of the stack can make use of it.
-	 */
-	if (ieee80211_cfg_on_oper_channel(sdata->local)
-	    && (channel == sdata->local->oper_channel))
-		return RX_CONTINUE;
-
 	dev_kfree_skb(skb);
 	return RX_QUEUED;
 }
@@ -264,8 +256,6 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
 				       bool was_hw_scan)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
-	bool on_oper_chan;
-	bool enable_beacons = false;
 
 	lockdep_assert_held(&local->mtx);
 
@@ -298,25 +288,11 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
 	local->scanning = 0;
 	local->scan_channel = NULL;
 
-	on_oper_chan = ieee80211_cfg_on_oper_channel(local);
-
-	if (was_hw_scan || !on_oper_chan)
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
-	else
-		/* Set power back to normal operating levels. */
-		ieee80211_hw_config(local, 0);
-
+	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 	if (!was_hw_scan) {
-		bool on_oper_chan2;
 		ieee80211_configure_filter(local);
 		drv_sw_scan_complete(local);
-		on_oper_chan2 = ieee80211_cfg_on_oper_channel(local);
-		/* We should always be on-channel at this point. */
-		WARN_ON(!on_oper_chan2);
-		if (on_oper_chan2 && (on_oper_chan != on_oper_chan2))
-			enable_beacons = true;
-
-		ieee80211_offchannel_return(local, enable_beacons, true);
+		ieee80211_offchannel_return(local, true);
 	}
 
 	ieee80211_recalc_idle(local);
@@ -357,15 +333,13 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 	 */
 	drv_sw_scan_start(local);
 
+	ieee80211_offchannel_stop_beaconing(local);
+
 	local->leave_oper_channel_time = 0;
 	local->next_scan_state = SCAN_DECISION;
 	local->scan_channel_idx = 0;
 
-	/* We always want to use off-channel PS, even if we
-	 * are not really leaving oper-channel.  Don't
-	 * tell the AP though, as long as we are on-channel.
-	 */
-	ieee80211_offchannel_enable_all_ps(local, false);
+	drv_flush(local, false);
 
 	ieee80211_configure_filter(local);
 
@@ -508,20 +482,7 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 	}
 	mutex_unlock(&local->iflist_mtx);
 
-	next_chan = local->scan_req->channels[local->scan_channel_idx];
-
-	if (ieee80211_cfg_on_oper_channel(local)) {
-		/* We're currently on operating channel. */
-		if (next_chan == local->oper_channel)
-			/* We don't need to move off of operating channel. */
-			local->next_scan_state = SCAN_SET_CHANNEL;
-		else
-			/*
-			 * We do need to leave operating channel, as next
-			 * scan is somewhere else.
-			 */
-			local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
-	} else {
+	if (local->scan_channel) {
 		/*
 		 * we're currently scanning a different channel, let's
 		 * see if we can scan another channel without interfering
@@ -537,6 +498,7 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 		 *
 		 * Otherwise switch back to the operating channel.
 		 */
+		next_chan = local->scan_req->channels[local->scan_channel_idx];
 
 		bad_latency = time_after(jiffies +
 				ieee80211_scan_get_channel_time(next_chan),
@@ -554,6 +516,12 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 			local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
 		else
 			local->next_scan_state = SCAN_SET_CHANNEL;
+	} else {
+		/*
+		 * we're on the operating channel currently, let's
+		 * leave that channel now to scan another one
+		 */
+		local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
 	}
 
 	*next_delay = 0;
@@ -562,10 +530,9 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
 						    unsigned long *next_delay)
 {
-	/* PS will already be in off-channel mode,
-	 * we do that once at the beginning of scanning.
-	 */
-	ieee80211_offchannel_stop_vifs(local, false);
+	ieee80211_offchannel_stop_station(local);
+
+	__set_bit(SCAN_OFF_CHANNEL, &local->scanning);
 
 	/*
 	 * What if the nullfunc frames didn't arrive?
@@ -588,15 +555,15 @@ static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *loca
 {
 	/* switch back to the operating channel */
 	local->scan_channel = NULL;
-	if (!ieee80211_cfg_on_oper_channel(local))
-		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 
 	/*
-	 * Re-enable vifs and beaconing.  Leave PS
-	 * in off-channel state..will put that back
-	 * on-channel at the end of scanning.
+	 * Only re-enable station mode interface now; beaconing will be
+	 * re-enabled once the full scan has been completed.
 	 */
-	ieee80211_offchannel_return(local, true, false);
+	ieee80211_offchannel_return(local, false);
+
+	__clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
 
 	*next_delay = HZ / 5;
 	local->next_scan_state = SCAN_DECISION;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1f8b120..eff1f4e 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -259,8 +259,7 @@ ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
 		return TX_CONTINUE;
 
-	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
-	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
+	if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) &&
 	    !ieee80211_is_probe_req(hdr->frame_control) &&
 	    !ieee80211_is_nullfunc(hdr->frame_control))
 		/*
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index 6c53b6d..99165ef 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -899,26 +899,6 @@ static bool ieee80211_work_ct_coexists(enum nl80211_channel_type wk_ct,
 	return false;
 }
 
-static enum nl80211_channel_type
-ieee80211_calc_ct(enum nl80211_channel_type wk_ct,
-		  enum nl80211_channel_type oper_ct)
-{
-	switch (wk_ct) {
-	case NL80211_CHAN_NO_HT:
-		return oper_ct;
-	case NL80211_CHAN_HT20:
-		if (oper_ct != NL80211_CHAN_NO_HT)
-			return oper_ct;
-		return wk_ct;
-	case NL80211_CHAN_HT40MINUS:
-	case NL80211_CHAN_HT40PLUS:
-		return wk_ct;
-	}
-	WARN_ON(1); /* shouldn't get here */
-	return wk_ct;
-}
-
-
 static void ieee80211_work_timer(unsigned long data)
 {
 	struct ieee80211_local *local = (void *) data;
@@ -969,52 +949,18 @@ static void ieee80211_work_work(struct work_struct *work)
 		}
 
 		if (!started && !local->tmp_channel) {
-			bool on_oper_chan;
-			bool tmp_chan_changed = false;
-			bool on_oper_chan2;
-			enum nl80211_channel_type wk_ct;
-			on_oper_chan = ieee80211_cfg_on_oper_channel(local);
-
-			/* Work with existing channel type if possible. */
-			wk_ct = wk->chan_type;
-			if (wk->chan == local->hw.conf.channel)
-				wk_ct = ieee80211_calc_ct(wk->chan_type,
-						local->hw.conf.channel_type);
-
-			if (local->tmp_channel)
-				if ((local->tmp_channel != wk->chan) ||
-				    (local->tmp_channel_type != wk_ct))
-					tmp_chan_changed = true;
-
-			local->tmp_channel = wk->chan;
-			local->tmp_channel_type = wk_ct;
 			/*
-			 * Leave the station vifs in awake mode if they
-			 * happen to be on the same channel as
-			 * the requested channel.
+			 * TODO: could optimize this by leaving the
+			 *	 station vifs in awake mode if they
+			 *	 happen to be on the same channel as
+			 *	 the requested channel
 			 */
-			on_oper_chan2 = ieee80211_cfg_on_oper_channel(local);
-			if (on_oper_chan != on_oper_chan2) {
-				if (on_oper_chan2) {
-					/* going off oper channel, PS too */
-					ieee80211_offchannel_stop_vifs(local,
-								       true);
-					ieee80211_hw_config(local, 0);
-				} else {
-					/* going on channel, but leave PS
-					 * off-channel. */
-					ieee80211_hw_config(local, 0);
-					ieee80211_offchannel_return(local,
-								    true,
-								    false);
-				}
-			} else if (tmp_chan_changed)
-				/* Still off-channel, but on some other
-				 * channel, so update hardware.
-				 * PS should already be off-channel.
-				 */
-				ieee80211_hw_config(local, 0);
+			ieee80211_offchannel_stop_beaconing(local);
+			ieee80211_offchannel_stop_station(local);
 
+			local->tmp_channel = wk->chan;
+			local->tmp_channel_type = wk->chan_type;
+			ieee80211_hw_config(local, 0);
 			started = true;
 			wk->timeout = jiffies;
 		}
@@ -1100,8 +1046,7 @@ static void ieee80211_work_work(struct work_struct *work)
 		 * we still need to do a hardware config.  Currently,
 		 * we cannot be here while scanning, however.
 		 */
-		if (!ieee80211_cfg_on_oper_channel(local))
-			ieee80211_hw_config(local, 0);
+		ieee80211_hw_config(local, 0);
 
 		/* At the least, we need to disable offchannel_ps,
 		 * so just go ahead and run the entire offchannel
@@ -1109,7 +1054,7 @@ static void ieee80211_work_work(struct work_struct *work)
 		 * beaconing if we were already on-oper-channel
 		 * as a future optimization.
 		 */
-		ieee80211_offchannel_return(local, true, true);
+		ieee80211_offchannel_return(local, true);
 
 		/* give connection some time to breathe */
 		run_again(local, jiffies + HZ/2);
-- 
1.7.7.4

