diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 85507bd..e1b0be7 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -14,6 +14,8 @@
 
 #include <linux/if_arp.h>
 #include <linux/rtnetlink.h>
+#include <linux/pm_qos_params.h>
+#include <net/sch_generic.h>
 #include <linux/slab.h>
 #include <net/mac80211.h>
 
@@ -83,7 +85,7 @@
 {
 	struct cfg80211_bss *cbss;
 	struct ieee80211_bss *bss;
-	int clen;
+	int clen, srlen;
 	s32 signal = 0;
 
 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
@@ -112,23 +114,24 @@
 		bss->dtim_period = tim_ie->dtim_period;
 	}
 
-	bss->supp_rates_len = 0;
+	/* replace old supported rates if we get new values */
+	srlen = 0;
 	if (elems->supp_rates) {
-		clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
+		clen = IEEE80211_MAX_SUPP_RATES;
 		if (clen > elems->supp_rates_len)
 			clen = elems->supp_rates_len;
-		memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates,
-		       clen);
-		bss->supp_rates_len += clen;
+		memcpy(bss->supp_rates, elems->supp_rates, clen);
+		srlen += clen;
 	}
 	if (elems->ext_supp_rates) {
-		clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len;
+		clen = IEEE80211_MAX_SUPP_RATES - srlen;
 		if (clen > elems->ext_supp_rates_len)
 			clen = elems->ext_supp_rates_len;
-		memcpy(&bss->supp_rates[bss->supp_rates_len],
-		       elems->ext_supp_rates, clen);
-		bss->supp_rates_len += clen;
+		memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen);
+		srlen += clen;
 	}
+	if (srlen)
+		bss->supp_rates_len = srlen;
 
 	bss->wmm_used = elems->wmm_param || elems->wmm_info;
 	bss->uapsd_supported = is_uapsd_supported(elems);
@@ -246,6 +249,8 @@
 	struct ieee80211_local *local = hw_to_local(hw);
 	bool was_hw_scan;
 
+	trace_api_scan_completed(local, aborted);
+
 	mutex_lock(&local->scan_mtx);
 
 	/*
@@ -322,6 +327,7 @@
 
 	ieee80211_offchannel_stop_beaconing(local);
 
+	local->leave_oper_channel_time = 0;
 	local->next_scan_state = SCAN_DECISION;
 	local->scan_channel_idx = 0;
 
@@ -406,7 +412,7 @@
 
 	if (local->ops->hw_scan) {
 		WARN_ON(!ieee80211_prep_hw_scan(local));
-		rc = drv_hw_scan(local, local->hw_scan_req);
+		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 	} else
 		rc = ieee80211_start_sw_scan(local);
 
@@ -426,11 +432,28 @@
 	return rc;
 }
 
+static unsigned long
+ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
+{
+	/*
+	 * TODO: channel switching also consumes quite some time,
+	 * add that delay as well to get a better estimation
+	 */
+	if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
+		return IEEE80211_PASSIVE_CHANNEL_TIME;
+	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
+}
+
 static int ieee80211_scan_state_decision(struct ieee80211_local *local,
 					 unsigned long *next_delay)
 {
 	bool associated = false;
+	bool tx_empty = true;
+	bool bad_latency;
+	bool listen_int_exceeded;
+	unsigned long min_beacon_int = 0;
 	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_channel *next_chan;
 
 	/* if no more bands/channels left, complete scan and advance to the idle state */
 	if (local->scan_channel_idx >= local->scan_req->n_channels) {
@@ -438,7 +461,11 @@
 		return 1;
 	}
 
-	/* check if at least one STA interface is associated */
+	/*
+	 * check if at least one STA interface is associated,
+	 * check if at least one STA interface has pending tx frames
+	 * and grab the lowest used beacon interval
+	 */
 	mutex_lock(&local->iflist_mtx);
 	list_for_each_entry(sdata, &local->interfaces, list) {
 		if (!ieee80211_sdata_running(sdata))
@@ -447,7 +474,16 @@
 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 			if (sdata->u.mgd.associated) {
 				associated = true;
-				break;
+
+				if (sdata->vif.bss_conf.beacon_int <
+				    min_beacon_int || min_beacon_int == 0)
+					min_beacon_int =
+						sdata->vif.bss_conf.beacon_int;
+
+				if (!qdisc_all_tx_empty(sdata->dev)) {
+					tx_empty = false;
+					break;
+				}
 			}
 		}
 	}
@@ -456,11 +492,34 @@
 	if (local->scan_channel) {
 		/*
 		 * we're currently scanning a different channel, let's
-		 * switch back to the operating channel now if at least
-		 * one interface is associated. Otherwise just scan the
-		 * next channel
+		 * see if we can scan another channel without interfering
+		 * with the current traffic situation.
+		 *
+		 * Since we don't know if the AP has pending frames for us
+		 * we can only check for our tx queues and use the current
+		 * pm_qos requirements for rx. Hence, if no tx traffic occurs
+		 * at all we will scan as many channels in a row as the pm_qos
+		 * latency allows us to. Additionally we also check for the
+		 * currently negotiated listen interval to prevent losing
+		 * frames unnecessarily.
+		 *
+		 * Otherwise switch back to the operating channel.
 		 */
-		if (associated)
+		next_chan = local->scan_req->channels[local->scan_channel_idx];
+
+		bad_latency = time_after(jiffies +
+				ieee80211_scan_get_channel_time(next_chan),
+				local->leave_oper_channel_time +
+				usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
+
+		listen_int_exceeded = time_after(jiffies +
+				ieee80211_scan_get_channel_time(next_chan),
+				local->leave_oper_channel_time +
+				usecs_to_jiffies(min_beacon_int * 1024) *
+				local->hw.conf.listen_interval);
+
+		if (associated && ( !tx_empty || bad_latency ||
+		    listen_int_exceeded))
 			local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
 		else
 			local->next_scan_state = SCAN_SET_CHANNEL;
@@ -492,6 +551,9 @@
 	else
 		*next_delay = HZ / 10;
 
+	/* remember when we left the operating channel */
+	local->leave_oper_channel_time = jiffies;
+
 	/* advance to the next channel to be scanned */
 	local->next_scan_state = SCAN_SET_CHANNEL;
 }
@@ -594,7 +656,7 @@
 	}
 
 	if (local->hw_scan_req) {
-		int rc = drv_hw_scan(local, local->hw_scan_req);
+		int rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 		mutex_unlock(&local->scan_mtx);
 		if (rc)
 			ieee80211_scan_completed(&local->hw, true);
@@ -667,10 +729,12 @@
 }
 
 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
-				    const u8 *ssid, u8 ssid_len)
+				    const u8 *ssid, u8 ssid_len,
+				    struct ieee80211_channel *chan)
 {
 	struct ieee80211_local *local = sdata->local;
 	int ret = -EBUSY;
+	enum nl80211_band band;
 
 	mutex_lock(&local->scan_mtx);
 
@@ -678,6 +742,30 @@
 	if (local->scan_req)
 		goto unlock;
 
+	/* fill internal scan request */
+	if (!chan) {
+		int i, nchan = 0;
+
+		for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
+			if (!local->hw.wiphy->bands[band])
+				continue;
+			for (i = 0;
+			     i < local->hw.wiphy->bands[band]->n_channels;
+			     i++) {
+				local->int_scan_req->channels[nchan] =
+				    &local->hw.wiphy->bands[band]->channels[i];
+				nchan++;
+			}
+		}
+
+		local->int_scan_req->n_channels = nchan;
+	} else {
+		local->int_scan_req->channels[0] = chan;
+		local->int_scan_req->n_channels = 1;
+	}
+
+	local->int_scan_req->ssids = &local->scan_ssid;
+	local->int_scan_req->n_ssids = 1;
 	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
 	local->int_scan_req->ssids[0].ssid_len = ssid_len;