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>

1 files changed, 31 insertions, 37 deletions

diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 3d414411a96e..1b239beb0a11 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 ||