mac80211: Optimize scans on current operating channel.

This should decrease un-necessary flushes, on/off channel work, and channel changes in cases where the only scanned channel is the current operating channel. * Removes SCAN_OFF_CHANNEL flag, uses SDATA_STATE_OFFCHANNEL and is-scanning flags instead. * Add helper method to determine if we are currently configured for the operating channel. * Do no blindly go off/on channel in work.c Instead, only call appropriate on/off code when we really need to change channels. Always enable offchannel-ps mode when starting work, and disable it when we are done. * Consolidate ieee80211_offchannel_stop_station and ieee80211_offchannel_stop_beaconing, call it ieee80211_offchannel_stop_vifs instead. * Accept non-beacon frames when scanning on operating channel. * Scan state machine optimized to minimize on/off channel transitions. Also, when going on-channel, go ahead and re-enable beaconing. We're going to be there for 200ms, so seems like some useful beaconing could happen. Always enable offchannel-ps mode when starting software scan, and disable it when we are done. * Grab local->mtx earlier in __ieee80211_scan_completed_finish so that we are protected when calling hw_config(), etc. * Pass probe-responses up the stack if scanning on local channel, so that mlme can take a look. Signed-off-by: Ben Greear <greearb@candelatech.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Optimize scans on current operating channel.
This should decrease un-necessary flushes, on/off channel work, and channel changes in cases where the only scanned channel is the current operating channel. * Removes SCAN_OFF_CHANNEL flag, uses SDATA_STATE_OFFCHANNEL and is-scanning flags instead. * Add helper method to determine if we are currently configured for the operating channel. * Do no blindly go off/on channel in work.c Instead, only call appropriate on/off code when we really need to change channels. Always enable offchannel-ps mode when starting work, and disable it when we are done. * Consolidate ieee80211_offchannel_stop_station and ieee80211_offchannel_stop_beaconing, call it ieee80211_offchannel_stop_vifs instead. * Accept non-beacon frames when scanning on operating channel. * Scan state machine optimized to minimize on/off channel transitions. Also, when going on-channel, go ahead and re-enable beaconing. We're going to be there for 200ms, so seems like some useful beaconing could happen. Always enable offchannel-ps mode when starting software scan, and disable it when we are done. * Grab local->mtx earlier in __ieee80211_scan_completed_finish so that we are protected when calling hw_config(), etc. * Pass probe-responses up the stack if scanning on local channel, so that mlme can take a look. Signed-off-by: Ben Greear <greearb@candelatech.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Ben Greear · John W. Linville
1 parent cb8d61de2d
Showing 7 changed files with 214 additions and 89 deletions Side-by-side Diff
net/mac80211/ieee80211_i.h
net/mac80211/main.c
net/mac80211/offchannel.c
net/mac80211/rx.c
net/mac80211/scan.c
net/mac80211/tx.c
net/mac80211/work.c
@@ -655,8 +655,6 @@
  *	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
@@ -665,7 +663,6 @@
 enum {
 	SCAN_SW_SCANNING,
 	SCAN_HW_SCANNING,
-	SCAN_OFF_CHANNEL,
 	SCAN_COMPLETED,
 	SCAN_ABORTED,
 };
  
@@ -1148,10 +1145,14 @@
 			  struct ieee80211_bss *bss);
  
 /* off-channel helpers */
-void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local);
-void ieee80211_offchannel_stop_station(struct ieee80211_local *local);
+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_return(struct ieee80211_local *local,
-				 bool enable_beaconing);
+				 bool enable_beaconing,
+				 bool offchannel_ps_disable);
 void ieee80211_hw_roc_setup(struct ieee80211_local *local);
  
 /* interface handling */
@@ -98,6 +98,41 @@
 	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;
+		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;
  
  
  
  
@@ -110,21 +145,27 @@
  
 	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;
 		channel_type = NL80211_CHAN_NO_HT;
-		local->hw.conf.flags |= IEEE80211_CONF_OFFCHANNEL;
-	} else if (local->tmp_channel &&
-		   local->oper_channel != local->tmp_channel) {
+	} else if (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;
-		local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
 	}
+
+	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;
  
 	if (offchannel_flag || chan != local->hw.conf.channel ||
@@ -231,7 +272,7 @@
  
 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
 		if (local->quiescing || !ieee80211_sdata_running(sdata) ||
-		    test_bit(SCAN_SW_SCANNING, &local->scanning)) {
+		    test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) {
 			sdata->vif.bss_conf.enable_beacon = false;
 		} else {
 			/*
@@ -17,10 +17,14 @@
 #include "driver-trace.h"
  
 /*
- * inform AP that we will go to sleep so that it will buffer the frames
- * while we scan
+ * 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.
  */
-static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
+static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
+					   bool tell_ap)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
@@ -41,8 +45,8 @@
 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 	}
  
-	if (!(local->offchannel_ps_enabled) ||
-	    !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
+	if (tell_ap && (!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
@@ -77,6 +81,9 @@
 		 * 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) {
  
  
  
  
  
  
  
  
@@ -95,63 +102,61 @@
 	ieee80211_sta_reset_conn_monitor(sdata);
 }
  
-void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
+				    bool offchannel_ps_enable)
 {
 	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;
  
-		/* disable beaconing */
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
+			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
+
+		/* Check to see if we should 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);
  
-		/*
-		 * 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);
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
 			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_stop_station(struct ieee80211_local *local)
+void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
+					bool tell_ap)
 {
 	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) {
-			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
-			netif_tx_stop_all_queues(sdata->dev);
-			if (sdata->u.mgd.associated)
-				ieee80211_offchannel_ps_enable(sdata);
-		}
+		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+		    sdata->u.mgd.associated)
+			ieee80211_offchannel_ps_enable(sdata, tell_ap);
 	}
 	mutex_unlock(&local->iflist_mtx);
 }
  
 void ieee80211_offchannel_return(struct ieee80211_local *local,
-				 bool enable_beaconing)
+				 bool enable_beaconing,
+				 bool offchannel_ps_disable)
 {
 	struct ieee80211_sub_if_data *sdata;
  
@@ -161,7 +166,8 @@
 			continue;
  
 		/* Tell AP we're back */
-		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+		if (offchannel_ps_disable &&
+		    sdata->vif.type == NL80211_IFTYPE_STATION) {
 			if (sdata->u.mgd.associated)
 				ieee80211_offchannel_ps_disable(sdata);
 		}
@@ -181,7 +187,7 @@
 			netif_tx_wake_all_queues(sdata->dev);
 		}
  
-		/* re-enable beaconing */
+		/* Check to see if we should re-enable beaconing */
 		if (enable_beaconing &&
 		    (sdata->vif.type == NL80211_IFTYPE_AP ||
 		     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
@@ -409,16 +409,10 @@
 	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 		return RX_CONTINUE;
  
-	if (test_bit(SCAN_HW_SCANNING, &local->scanning))
+	if (test_bit(SCAN_HW_SCANNING, &local->scanning) ||
+	    test_bit(SCAN_SW_SCANNING, &local->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;
@@ -2793,7 +2787,7 @@
 		local->dot11ReceivedFragmentCount++;
  
 	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
-		     test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
+		     test_bit(SCAN_SW_SCANNING, &local->scanning)))
 		status->rx_flags |= IEEE80211_RX_IN_SCAN;
  
 	if (ieee80211_is_mgmt(fc))
@@ -212,6 +212,14 @@
 	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;
 }
  
  
  
  
@@ -293,15 +301,31 @@
 					      bool was_hw_scan)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
+	bool on_oper_chan;
+	bool enable_beacons = false;
  
-	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+	mutex_lock(&local->mtx);
+	on_oper_chan = ieee80211_cfg_on_oper_channel(local);
+
+	if (was_hw_scan || !on_oper_chan) {
+		if (WARN_ON(local->scan_channel))
+			local->scan_channel = NULL;
+		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);
-		ieee80211_offchannel_return(local, true);
+		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);
 	}
  
-	mutex_lock(&local->mtx);
 	ieee80211_recalc_idle(local);
 	mutex_unlock(&local->mtx);
  
  
@@ -341,13 +365,15 @@
 	 */
 	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;
  
-	drv_flush(local, false);
+	/* 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);
  
 	ieee80211_configure_filter(local);
  
@@ -487,7 +513,21 @@
 	}
 	mutex_unlock(&local->iflist_mtx);
  
-	if (local->scan_channel) {
+	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) &&
+		    (local->_oper_channel_type == NL80211_CHAN_NO_HT))
+			/* 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 {
 		/*
 		 * we're currently scanning a different channel, let's
 		 * see if we can scan another channel without interfering
@@ -503,7 +543,6 @@
 		 *
 		 * 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),
@@ -521,12 +560,6 @@
 			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;
  
@@ -535,10 +568,11 @@
 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
 						    unsigned long *next_delay)
 {
-	ieee80211_offchannel_stop_station(local);
+	/* PS will already be in off-channel mode,
+	 * we do that once at the beginning of scanning.
+	 */
+	ieee80211_offchannel_stop_vifs(local, false);
  
-	__set_bit(SCAN_OFF_CHANNEL, &local->scanning);
-
 	/*
 	 * What if the nullfunc frames didn't arrive?
 	 */
  
  
  
@@ -560,16 +594,16 @@
 {
 	/* switch back to the operating channel */
 	local->scan_channel = NULL;
-	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+	if (!ieee80211_cfg_on_oper_channel(local))
+		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
  
 	/*
-	 * Only re-enable station mode interface now; beaconing will be
-	 * re-enabled once the full scan has been completed.
+	 * Re-enable vifs and beaconing.  Leave PS
+	 * in off-channel state..will put that back
+	 * on-channel at the end of scanning.
 	 */
-	ieee80211_offchannel_return(local, false);
+	ieee80211_offchannel_return(local, true, false);
  
-	__clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
-
 	*next_delay = HZ / 5;
 	local->next_scan_state = SCAN_DECISION;
 }
@@ -584,8 +618,12 @@
 	chan = local->scan_req->channels[local->scan_channel_idx];
  
 	local->scan_channel = chan;
-	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
-		skip = 1;
+
+	/* Only call hw-config if we really need to change channels. */
+	if ((chan != local->hw.conf.channel) ||
+	    (local->hw.conf.channel_type != NL80211_CHAN_NO_HT))
+		if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
+			skip = 1;
  
 	/* advance state machine to next channel/band */
 	local->scan_channel_idx++;
@@ -257,7 +257,8 @@
 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
 		return TX_CONTINUE;
  
-	if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) &&
+	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
+	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
 	    !ieee80211_is_probe_req(hdr->frame_control) &&
 	    !ieee80211_is_nullfunc(hdr->frame_control))
 		/*
@@ -924,18 +924,44 @@
 		}
  
 		if (!started && !local->tmp_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
-			 */
-			ieee80211_offchannel_stop_beaconing(local);
-			ieee80211_offchannel_stop_station(local);
+			bool on_oper_chan;
+			bool tmp_chan_changed = false;
+			bool on_oper_chan2;
+			on_oper_chan = ieee80211_cfg_on_oper_channel(local);
+			if (local->tmp_channel)
+				if ((local->tmp_channel != wk->chan) ||
+				    (local->tmp_channel_type != wk->chan_type))
+					tmp_chan_changed = true;
  
 			local->tmp_channel = wk->chan;
 			local->tmp_channel_type = wk->chan_type;
-			ieee80211_hw_config(local, 0);
+			/*
+			 * Leave 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);
+
 			started = true;
 			wk->timeout = jiffies;
 		}
  
@@ -1011,9 +1037,27 @@
 	}
  
 	if (!remain_off_channel && local->tmp_channel) {
+		bool on_oper_chan = ieee80211_cfg_on_oper_channel(local);
 		local->tmp_channel = NULL;
-		ieee80211_hw_config(local, 0);
-		ieee80211_offchannel_return(local, true);
+		/* If tmp_channel wasn't operating channel, then
+		 * we need to go back on-channel.
+		 * NOTE:  If we can ever be here while scannning,
+		 * or if the hw_config() channel config logic changes,
+		 * then we may need to do a more thorough check to see if
+		 * we still need to do a hardware config.  Currently,
+		 * we cannot be here while scanning, however.
+		 */
+		if (ieee80211_cfg_on_oper_channel(local) && !on_oper_chan)
+			ieee80211_hw_config(local, 0);
+
+		/* At the least, we need to disable offchannel_ps,
+		 * so just go ahead and run the entire offchannel
+		 * return logic here.  We *could* skip enabling
+		 * beaconing if we were already on-oper-channel
+		 * as a future optimization.
+		 */
+		ieee80211_offchannel_return(local, true, true);
+
 		/* give connection some time to breathe */
 		run_again(local, jiffies + HZ/2);
 	}
...	...	@@ -655,8 +655,6 @@
655	655	* well be on the operating channel
656	656	* @SCAN_HW_SCANNING: The hardware is scanning for us, we have no way to
657	657	* determine if we are on the operating channel or not
658		- * @SCAN_OFF_CHANNEL: We're off our operating channel for scanning,
659		- * gets only set in conjunction with SCAN_SW_SCANNING
660	658	* @SCAN_COMPLETED: Set for our scan work function when the driver reported
661	659	* that the scan completed.
662	660	* @SCAN_ABORTED: Set for our scan work function when the driver reported
...	...	@@ -665,7 +663,6 @@
665	663	enum {
666	664	SCAN_SW_SCANNING,
667	665	SCAN_HW_SCANNING,
668		- SCAN_OFF_CHANNEL,
669	666	SCAN_COMPLETED,
670	667	SCAN_ABORTED,
671	668	};
672	669
...	...	@@ -1148,10 +1145,14 @@
1148	1145	struct ieee80211_bss *bss);
1149	1146
1150	1147	/* off-channel helpers */
1151		-void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local);
1152		-void ieee80211_offchannel_stop_station(struct ieee80211_local *local);
	1148	+bool ieee80211_cfg_on_oper_channel(struct ieee80211_local *local);
	1149	+void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
	1150	+ bool tell_ap);
	1151	+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
	1152	+ bool offchannel_ps_enable);
1153	1153	void ieee80211_offchannel_return(struct ieee80211_local *local,
1154		- bool enable_beaconing);
	1154	+ bool enable_beaconing,
	1155	+ bool offchannel_ps_disable);
1155	1156	void ieee80211_hw_roc_setup(struct ieee80211_local *local);
1156	1157
1157	1158	/* interface handling */
...	...	@@ -98,6 +98,41 @@
98	98	ieee80211_configure_filter(local);
99	99	}
100	100
	101	+/*
	102	+ * Returns true if we are logically configured to be on
	103	+ * the operating channel AND the hardware-conf is currently
	104	+ * configured on the operating channel. Compares channel-type
	105	+ * as well.
	106	+ */
	107	+bool ieee80211_cfg_on_oper_channel(struct ieee80211_local *local)
	108	+{
	109	+ struct ieee80211_channel chan, scan_chan;
	110	+ enum nl80211_channel_type channel_type;
	111	+
	112	+ /* This logic needs to match logic in ieee80211_hw_config */
	113	+ if (local->scan_channel) {
	114	+ chan = local->scan_channel;
	115	+ channel_type = NL80211_CHAN_NO_HT;
	116	+ } else if (local->tmp_channel) {
	117	+ chan = scan_chan = local->tmp_channel;
	118	+ channel_type = local->tmp_channel_type;
	119	+ } else {
	120	+ chan = local->oper_channel;
	121	+ channel_type = local->_oper_channel_type;
	122	+ }
	123	+
	124	+ if (chan != local->oper_channel \|\|
	125	+ channel_type != local->_oper_channel_type)
	126	+ return false;
	127	+
	128	+ /* Check current hardware-config against oper_channel. */
	129	+ if ((local->oper_channel != local->hw.conf.channel) \|\|
	130	+ (local->_oper_channel_type != local->hw.conf.channel_type))
	131	+ return false;
	132	+
	133	+ return true;
	134	+}
	135	+
101	136	int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
102	137	{
103	138	struct ieee80211_channel chan, scan_chan;
104	139
105	140
106	141
107	142
...	...	@@ -110,21 +145,27 @@
110	145
111	146	scan_chan = local->scan_channel;
112	147
	148	+ /* If this off-channel logic ever changes, ieee80211_on_oper_channel
	149	+ * may need to change as well.
	150	+ */
113	151	offchannel_flag = local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
114	152	if (scan_chan) {
115	153	chan = scan_chan;
116	154	channel_type = NL80211_CHAN_NO_HT;
117		- local->hw.conf.flags \|= IEEE80211_CONF_OFFCHANNEL;
118		- } else if (local->tmp_channel &&
119		- local->oper_channel != local->tmp_channel) {
	155	+ } else if (local->tmp_channel) {
120	156	chan = scan_chan = local->tmp_channel;
121	157	channel_type = local->tmp_channel_type;
122		- local->hw.conf.flags \|= IEEE80211_CONF_OFFCHANNEL;
123	158	} else {
124	159	chan = local->oper_channel;
125	160	channel_type = local->_oper_channel_type;
126		- local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
127	161	}
	162	+
	163	+ if (chan != local->oper_channel \|\|
	164	+ channel_type != local->_oper_channel_type)
	165	+ local->hw.conf.flags \|= IEEE80211_CONF_OFFCHANNEL;
	166	+ else
	167	+ local->hw.conf.flags &= ~IEEE80211_CONF_OFFCHANNEL;
	168	+
128	169	offchannel_flag ^= local->hw.conf.flags & IEEE80211_CONF_OFFCHANNEL;
129	170
130	171	if (offchannel_flag \|\| chan != local->hw.conf.channel \|\|
...	...	@@ -231,7 +272,7 @@
231	272
232	273	if (changed & BSS_CHANGED_BEACON_ENABLED) {
233	274	if (local->quiescing \|\| !ieee80211_sdata_running(sdata) \|\|
234		- test_bit(SCAN_SW_SCANNING, &local->scanning)) {
	275	+ test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state)) {
235	276	sdata->vif.bss_conf.enable_beacon = false;
236	277	} else {
237	278	/*
...	...	@@ -17,10 +17,14 @@
17	17	#include "driver-trace.h"
18	18
19	19	/*
20		- * inform AP that we will go to sleep so that it will buffer the frames
21		- * while we scan
	20	+ * Tell our hardware to disable PS.
	21	+ * Optionally inform AP that we will go to sleep so that it will buffer
	22	+ * the frames while we are doing off-channel work. This is optional
	23	+ * because we may be doing work on-operating channel, and want our
	24	+ * hardware unconditionally awake, but still let the AP send us normal frames.
22	25	*/
23		-static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
	26	+static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
	27	+ bool tell_ap)
24	28	{
25	29	struct ieee80211_local *local = sdata->local;
26	30	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
...	...	@@ -41,8 +45,8 @@
41	45	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
42	46	}
43	47
44		- if (!(local->offchannel_ps_enabled) \|\|
45		- !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
	48	+ if (tell_ap && (!local->offchannel_ps_enabled \|\|
	49	+ !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)))
46	50	/*
47	51	* If power save was enabled, no need to send a nullfunc
48	52	* frame because AP knows that we are sleeping. But if the
...	...	@@ -77,6 +81,9 @@
77	81	* we are sleeping, let's just enable power save mode in
78	82	* hardware.
79	83	*/
	84	+ /* TODO: Only set hardware if CONF_PS changed?
	85	+ * TODO: Should we set offchannel_ps_enabled to false?
	86	+ */
80	87	local->hw.conf.flags \|= IEEE80211_CONF_PS;
81	88	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
82	89	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
83	90
84	91
85	92
86	93
87	94
88	95
89	96
90	97
...	...	@@ -95,63 +102,61 @@
95	102	ieee80211_sta_reset_conn_monitor(sdata);
96	103	}
97	104
98		-void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
	105	+void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
	106	+ bool offchannel_ps_enable)
99	107	{
100	108	struct ieee80211_sub_if_data *sdata;
101	109
	110	+ /*
	111	+ * notify the AP about us leaving the channel and stop all
	112	+ * STA interfaces.
	113	+ */
102	114	mutex_lock(&local->iflist_mtx);
103	115	list_for_each_entry(sdata, &local->interfaces, list) {
104	116	if (!ieee80211_sdata_running(sdata))
105	117	continue;
106	118
107		- /* disable beaconing */
	119	+ if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
	120	+ set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
	121	+
	122	+ /* Check to see if we should disable beaconing. */
108	123	if (sdata->vif.type == NL80211_IFTYPE_AP \|\|
109	124	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
110	125	sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
111	126	ieee80211_bss_info_change_notify(
112	127	sdata, BSS_CHANGED_BEACON_ENABLED);
113	128
114		- /*
115		- * only handle non-STA interfaces here, STA interfaces
116		- * are handled in ieee80211_offchannel_stop_station(),
117		- * e.g., from the background scan state machine.
118		- *
119		- * In addition, do not stop monitor interface to allow it to be
120		- * used from user space controlled off-channel operations.
121		- */
122		- if (sdata->vif.type != NL80211_IFTYPE_STATION &&
123		- sdata->vif.type != NL80211_IFTYPE_MONITOR) {
124		- set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
	129	+ if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
125	130	netif_tx_stop_all_queues(sdata->dev);
	131	+ if (offchannel_ps_enable &&
	132	+ (sdata->vif.type == NL80211_IFTYPE_STATION) &&
	133	+ sdata->u.mgd.associated)
	134	+ ieee80211_offchannel_ps_enable(sdata, true);
126	135	}
127	136	}
128	137	mutex_unlock(&local->iflist_mtx);
129	138	}
130	139
131		-void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
	140	+void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
	141	+ bool tell_ap)
132	142	{
133	143	struct ieee80211_sub_if_data *sdata;
134	144
135		- /*
136		- * notify the AP about us leaving the channel and stop all STA interfaces
137		- */
138	145	mutex_lock(&local->iflist_mtx);
139	146	list_for_each_entry(sdata, &local->interfaces, list) {
140	147	if (!ieee80211_sdata_running(sdata))
141	148	continue;
142	149
143		- if (sdata->vif.type == NL80211_IFTYPE_STATION) {
144		- set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
145		- netif_tx_stop_all_queues(sdata->dev);
146		- if (sdata->u.mgd.associated)
147		- ieee80211_offchannel_ps_enable(sdata);
148		- }
	150	+ if (sdata->vif.type == NL80211_IFTYPE_STATION &&
	151	+ sdata->u.mgd.associated)
	152	+ ieee80211_offchannel_ps_enable(sdata, tell_ap);
149	153	}
150	154	mutex_unlock(&local->iflist_mtx);
151	155	}
152	156
153	157	void ieee80211_offchannel_return(struct ieee80211_local *local,
154		- bool enable_beaconing)
	158	+ bool enable_beaconing,
	159	+ bool offchannel_ps_disable)
155	160	{
156	161	struct ieee80211_sub_if_data *sdata;
157	162
...	...	@@ -161,7 +166,8 @@
161	166	continue;
162	167
163	168	/* Tell AP we're back */
164		- if (sdata->vif.type == NL80211_IFTYPE_STATION) {
	169	+ if (offchannel_ps_disable &&
	170	+ sdata->vif.type == NL80211_IFTYPE_STATION) {
165	171	if (sdata->u.mgd.associated)
166	172	ieee80211_offchannel_ps_disable(sdata);
167	173	}
...	...	@@ -181,7 +187,7 @@
181	187	netif_tx_wake_all_queues(sdata->dev);
182	188	}
183	189
184		- /* re-enable beaconing */
	190	+ /* Check to see if we should re-enable beaconing */
185	191	if (enable_beaconing &&
186	192	(sdata->vif.type == NL80211_IFTYPE_AP \|\|
187	193	sdata->vif.type == NL80211_IFTYPE_ADHOC \|\|
...	...	@@ -409,16 +409,10 @@
409	409	if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
410	410	return RX_CONTINUE;
411	411
412		- if (test_bit(SCAN_HW_SCANNING, &local->scanning))
	412	+ if (test_bit(SCAN_HW_SCANNING, &local->scanning) \|\|
	413	+ test_bit(SCAN_SW_SCANNING, &local->scanning))
413	414	return ieee80211_scan_rx(rx->sdata, skb);
414	415
415		- if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
416		- /* drop all the other packets during a software scan anyway */
417		- if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
418		- dev_kfree_skb(skb);
419		- return RX_QUEUED;
420		- }
421		-
422	416	/* scanning finished during invoking of handlers */
423	417	I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
424	418	return RX_DROP_UNUSABLE;
...	...	@@ -2793,7 +2787,7 @@
2793	2787	local->dot11ReceivedFragmentCount++;
2794	2788
2795	2789	if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) \|\|
2796		- test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
	2790	+ test_bit(SCAN_SW_SCANNING, &local->scanning)))
2797	2791	status->rx_flags \|= IEEE80211_RX_IN_SCAN;
2798	2792
2799	2793	if (ieee80211_is_mgmt(fc))
...	...	@@ -212,6 +212,14 @@
212	212	if (bss)
213	213	ieee80211_rx_bss_put(sdata->local, bss);
214	214
	215	+ /* If we are on-operating-channel, and this packet is for the
	216	+ * current channel, pass the pkt on up the stack so that
	217	+ * the rest of the stack can make use of it.
	218	+ */
	219	+ if (ieee80211_cfg_on_oper_channel(sdata->local)
	220	+ && (channel == sdata->local->oper_channel))
	221	+ return RX_CONTINUE;
	222	+
215	223	dev_kfree_skb(skb);
216	224	return RX_QUEUED;
217	225	}
218	226
219	227
220	228
221	229
...	...	@@ -293,15 +301,31 @@
293	301	bool was_hw_scan)
294	302	{
295	303	struct ieee80211_local *local = hw_to_local(hw);
	304	+ bool on_oper_chan;
	305	+ bool enable_beacons = false;
296	306
297		- ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	307	+ mutex_lock(&local->mtx);
	308	+ on_oper_chan = ieee80211_cfg_on_oper_channel(local);
	309	+
	310	+ if (was_hw_scan \|\| !on_oper_chan) {
	311	+ if (WARN_ON(local->scan_channel))
	312	+ local->scan_channel = NULL;
	313	+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	314	+ }
	315	+
298	316	if (!was_hw_scan) {
	317	+ bool on_oper_chan2;
299	318	ieee80211_configure_filter(local);
300	319	drv_sw_scan_complete(local);
301		- ieee80211_offchannel_return(local, true);
	320	+ on_oper_chan2 = ieee80211_cfg_on_oper_channel(local);
	321	+ /* We should always be on-channel at this point. */
	322	+ WARN_ON(!on_oper_chan2);
	323	+ if (on_oper_chan2 && (on_oper_chan != on_oper_chan2))
	324	+ enable_beacons = true;
	325	+
	326	+ ieee80211_offchannel_return(local, enable_beacons, true);
302	327	}
303	328
304		- mutex_lock(&local->mtx);
305	329	ieee80211_recalc_idle(local);
306	330	mutex_unlock(&local->mtx);
307	331
308	332
...	...	@@ -341,13 +365,15 @@
341	365	*/
342	366	drv_sw_scan_start(local);
343	367
344		- ieee80211_offchannel_stop_beaconing(local);
345		-
346	368	local->leave_oper_channel_time = 0;
347	369	local->next_scan_state = SCAN_DECISION;
348	370	local->scan_channel_idx = 0;
349	371
350		- drv_flush(local, false);
	372	+ /* We always want to use off-channel PS, even if we
	373	+ * are not really leaving oper-channel. Don't
	374	+ * tell the AP though, as long as we are on-channel.
	375	+ */
	376	+ ieee80211_offchannel_enable_all_ps(local, false);
351	377
352	378	ieee80211_configure_filter(local);
353	379
...	...	@@ -487,7 +513,21 @@
487	513	}
488	514	mutex_unlock(&local->iflist_mtx);
489	515
490		- if (local->scan_channel) {
	516	+ next_chan = local->scan_req->channels[local->scan_channel_idx];
	517	+
	518	+ if (ieee80211_cfg_on_oper_channel(local)) {
	519	+ /* We're currently on operating channel. */
	520	+ if ((next_chan == local->oper_channel) &&
	521	+ (local->_oper_channel_type == NL80211_CHAN_NO_HT))
	522	+ /* We don't need to move off of operating channel. */
	523	+ local->next_scan_state = SCAN_SET_CHANNEL;
	524	+ else
	525	+ /*
	526	+ * We do need to leave operating channel, as next
	527	+ * scan is somewhere else.
	528	+ */
	529	+ local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
	530	+ } else {
491	531	/*
492	532	* we're currently scanning a different channel, let's
493	533	* see if we can scan another channel without interfering
...	...	@@ -503,7 +543,6 @@
503	543	*
504	544	* Otherwise switch back to the operating channel.
505	545	*/
506		- next_chan = local->scan_req->channels[local->scan_channel_idx];
507	546
508	547	bad_latency = time_after(jiffies +
509	548	ieee80211_scan_get_channel_time(next_chan),
...	...	@@ -521,12 +560,6 @@
521	560	local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
522	561	else
523	562	local->next_scan_state = SCAN_SET_CHANNEL;
524		- } else {
525		- /*
526		- * we're on the operating channel currently, let's
527		- * leave that channel now to scan another one
528		- */
529		- local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
530	563	}
531	564
532	565	*next_delay = 0;
533	566
...	...	@@ -535,10 +568,11 @@
535	568	static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
536	569	unsigned long *next_delay)
537	570	{
538		- ieee80211_offchannel_stop_station(local);
	571	+ /* PS will already be in off-channel mode,
	572	+ * we do that once at the beginning of scanning.
	573	+ */
	574	+ ieee80211_offchannel_stop_vifs(local, false);
539	575
540		- __set_bit(SCAN_OFF_CHANNEL, &local->scanning);
541		-
542	576	/*
543	577	* What if the nullfunc frames didn't arrive?
544	578	*/
545	579
546	580
547	581
...	...	@@ -560,16 +594,16 @@
560	594	{
561	595	/* switch back to the operating channel */
562	596	local->scan_channel = NULL;
563		- ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	597	+ if (!ieee80211_cfg_on_oper_channel(local))
	598	+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
564	599
565	600	/*
566		- * Only re-enable station mode interface now; beaconing will be
567		- * re-enabled once the full scan has been completed.
	601	+ * Re-enable vifs and beaconing. Leave PS
	602	+ * in off-channel state..will put that back
	603	+ * on-channel at the end of scanning.
568	604	*/
569		- ieee80211_offchannel_return(local, false);
	605	+ ieee80211_offchannel_return(local, true, false);
570	606
571		- __clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
572		-
573	607	*next_delay = HZ / 5;
574	608	local->next_scan_state = SCAN_DECISION;
575	609	}
...	...	@@ -584,8 +618,12 @@
584	618	chan = local->scan_req->channels[local->scan_channel_idx];
585	619
586	620	local->scan_channel = chan;
587		- if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
588		- skip = 1;
	621	+
	622	+ /* Only call hw-config if we really need to change channels. */
	623	+ if ((chan != local->hw.conf.channel) \|\|
	624	+ (local->hw.conf.channel_type != NL80211_CHAN_NO_HT))
	625	+ if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
	626	+ skip = 1;
589	627
590	628	/* advance state machine to next channel/band */
591	629	local->scan_channel_idx++;
...	...	@@ -257,7 +257,8 @@
257	257	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
258	258	return TX_CONTINUE;
259	259
260		- if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) &&
	260	+ if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
	261	+ test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
261	262	!ieee80211_is_probe_req(hdr->frame_control) &&
262	263	!ieee80211_is_nullfunc(hdr->frame_control))
263	264	/*
...	...	@@ -924,18 +924,44 @@
924	924	}
925	925
926	926	if (!started && !local->tmp_channel) {
927		- /*
928		- * TODO: could optimize this by leaving the
929		- * station vifs in awake mode if they
930		- * happen to be on the same channel as
931		- * the requested channel
932		- */
933		- ieee80211_offchannel_stop_beaconing(local);
934		- ieee80211_offchannel_stop_station(local);
	927	+ bool on_oper_chan;
	928	+ bool tmp_chan_changed = false;
	929	+ bool on_oper_chan2;
	930	+ on_oper_chan = ieee80211_cfg_on_oper_channel(local);
	931	+ if (local->tmp_channel)
	932	+ if ((local->tmp_channel != wk->chan) \|\|
	933	+ (local->tmp_channel_type != wk->chan_type))
	934	+ tmp_chan_changed = true;
935	935
936	936	local->tmp_channel = wk->chan;
937	937	local->tmp_channel_type = wk->chan_type;
938		- ieee80211_hw_config(local, 0);
	938	+ /*
	939	+ * Leave the station vifs in awake mode if they
	940	+ * happen to be on the same channel as
	941	+ * the requested channel.
	942	+ */
	943	+ on_oper_chan2 = ieee80211_cfg_on_oper_channel(local);
	944	+ if (on_oper_chan != on_oper_chan2) {
	945	+ if (on_oper_chan2) {
	946	+ /* going off oper channel, PS too */
	947	+ ieee80211_offchannel_stop_vifs(local,
	948	+ true);
	949	+ ieee80211_hw_config(local, 0);
	950	+ } else {
	951	+ /* going on channel, but leave PS
	952	+ * off-channel. */
	953	+ ieee80211_hw_config(local, 0);
	954	+ ieee80211_offchannel_return(local,
	955	+ true,
	956	+ false);
	957	+ }
	958	+ } else if (tmp_chan_changed)
	959	+ /* Still off-channel, but on some other
	960	+ * channel, so update hardware.
	961	+ * PS should already be off-channel.
	962	+ */
	963	+ ieee80211_hw_config(local, 0);
	964	+
939	965	started = true;
940	966	wk->timeout = jiffies;
941	967	}
942	968
...	...	@@ -1011,9 +1037,27 @@
1011	1037	}
1012	1038
1013	1039	if (!remain_off_channel && local->tmp_channel) {
	1040	+ bool on_oper_chan = ieee80211_cfg_on_oper_channel(local);
1014	1041	local->tmp_channel = NULL;
1015		- ieee80211_hw_config(local, 0);
1016		- ieee80211_offchannel_return(local, true);
	1042	+ /* If tmp_channel wasn't operating channel, then
	1043	+ * we need to go back on-channel.
	1044	+ * NOTE: If we can ever be here while scannning,
	1045	+ * or if the hw_config() channel config logic changes,
	1046	+ * then we may need to do a more thorough check to see if
	1047	+ * we still need to do a hardware config. Currently,
	1048	+ * we cannot be here while scanning, however.
	1049	+ */
	1050	+ if (ieee80211_cfg_on_oper_channel(local) && !on_oper_chan)
	1051	+ ieee80211_hw_config(local, 0);
	1052	+
	1053	+ /* At the least, we need to disable offchannel_ps,
	1054	+ * so just go ahead and run the entire offchannel
	1055	+ * return logic here. We could skip enabling
	1056	+ * beaconing if we were already on-oper-channel
	1057	+ * as a future optimization.
	1058	+ */
	1059	+ ieee80211_offchannel_return(local, true, true);
	1060	+
1017	1061	/* give connection some time to breathe */
1018	1062	run_again(local, jiffies + HZ/2);
1019	1063	}