mac80211: synchronize scan off/on-channel and PS states

commit aacde9ee upstream.

Since:

commit b23b025f
Author: Ben Greear <greearb@candelatech.com>
Date:   Fri Feb 4 11:54:17 2011 -0800

    mac80211: Optimize scans on current operating channel.

we do not disable PS while going back to operational channel (on
ieee80211_scan_state_suspend) and deffer that until scan finish.
But since we are allowed to send frames, we can send a frame to AP
without PM bit set, so disable PS on AP side. Then when we switch
to off-channel (in ieee80211_scan_state_resume) we do not enable PS.
Hence we are off-channel with PS disabled, frames are not buffered
by AP.

To fix remove offchannel_ps_disable argument and always enable PS when
going off-channel and disable it when going on-channel, like it was
before.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/mac80211/ieee80211_i.h

@@ -1169,11 +1169,9 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work);
 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_vifs(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 */

net/mac80211/offchannel.c

@@ -102,8 +102,7 @@ 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_vifs(struct ieee80211_local *local)
 {
 	struct ieee80211_sub_if_data *sdata;
 
@@ -128,8 +127,7 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
 
 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
 			netif_tx_stop_all_queues(sdata->dev);
-			if (offchannel_ps_enable &&
-			    (sdata->vif.type == NL80211_IFTYPE_STATION) &&
+			if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 			    sdata->u.mgd.associated)
 				ieee80211_offchannel_ps_enable(sdata, true);
 		}
@@ -155,8 +153,7 @@ void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
 }
 
 void ieee80211_offchannel_return(struct ieee80211_local *local,
-				 bool enable_beaconing,
-				 bool offchannel_ps_disable)
+				 bool enable_beaconing)
 {
 	struct ieee80211_sub_if_data *sdata;
 
@@ -166,11 +163,9 @@ 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->u.mgd.associated)
-				ieee80211_offchannel_ps_disable(sdata);
-		}
+		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+		    sdata->u.mgd.associated)
+			ieee80211_offchannel_ps_disable(sdata);
 
 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
 			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);

net/mac80211/scan.c

@@ -314,7 +314,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
 		if (on_oper_chan2 && (on_oper_chan != on_oper_chan2))
 			enable_beacons = true;
 
-		ieee80211_offchannel_return(local, enable_beacons, true);
+		ieee80211_offchannel_return(local, enable_beacons);
 	}
 
 	ieee80211_recalc_idle(local);
@@ -563,7 +563,7 @@ static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *loca
 	/* 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_vifs(local);
 
 	/*
 	 * What if the nullfunc frames didn't arrive?
@@ -594,7 +594,7 @@ static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *loca
 	 * in off-channel state..will put that back
 	 * on-channel at the end of scanning.
 	 */
-	ieee80211_offchannel_return(local, true, false);
+	ieee80211_offchannel_return(local, true);
 
 	*next_delay = HZ / 5;
 	local->next_scan_state = SCAN_DECISION;

net/mac80211/work.c

@@ -973,16 +973,14 @@ static void ieee80211_work_work(struct work_struct *work)
 			if (on_oper_chan != on_oper_chan2) {
 				if (on_oper_chan2) {
 					/* going off oper channel, PS too */
-					ieee80211_offchannel_stop_vifs(local,
-								       true);
+					ieee80211_offchannel_stop_vifs(local);
 					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);
+								    true);
 				}
 			} else if (tmp_chan_changed)
 				/* Still off-channel, but on some other
@@ -1085,7 +1083,7 @@ 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);