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, 22 insertions, 55 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 105436dbb90d..5279300163a5 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;