1 files changed, 107 insertions, 19 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 85507bd9e341..e1b0be7a57b9 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 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
 {
         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 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
                 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 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
         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 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 
         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 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 
         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 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
         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 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local,
                 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 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local,
                 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 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local,
         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 @@ static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *loca
         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 @@ void ieee80211_scan_work(struct work_struct *work)
         }
 
         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_scan(struct ieee80211_sub_if_data *sdata,
 }
 
 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 @@ int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
         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;