CHROMIUMOS: mac80211: Use different probe counts on resume

We recently increased the probe retry count for beacon monitoring
in order to make challenging channel conditions less volatile.  In
doing so, we made the system slower to respond to a lost AP when the
system resumes from suspend.  Mitigate this by using a different
try-count for the resume-from-suspend case.

BUG=chromium-os:28576
TEST=Manual: Suspend, unplug AP, resume.  Observe disconnection in < 1sec

Change-Id: I206d4b2838da2ce7da00739412e5fcda63a27a2c
Signed-off-by: Paul Stewart <pstew@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/19234
Reviewed-by: Gary Morain <gmorain@chromium.org>

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index db8fae5..4b53162 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -378,6 +378,7 @@ enum ieee80211_sta_flags {
        IEEE80211_STA_UAPSD_ENABLED     = BIT(7),
        IEEE80211_STA_NULLFUNC_ACKED    = BIT(8),
        IEEE80211_STA_RESET_SIGNAL_AVE  = BIT(9),
+       IEEE80211_STA_RESUME_POLL       = BIT(10),
 };
 
 struct ieee80211_mgd_auth_data {

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 364dc45..d1f2e8c 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -41,6 +41,12 @@ module_param(max_nullfunc_tries, int, 0644);
 MODULE_PARM_DESC(max_nullfunc_tries,
                 "Maximum nullfunc tx tries before disconnecting (reason 4).");
 
+static int max_nullfunc_tries_resume = 2;
+module_param(max_nullfunc_tries_resume, int, 0644);
+MODULE_PARM_DESC(max_nullfunc_tries_resume,
+                "Maximum nullfunc tx tries on resume before disconnecting "
+                "(reason 4).");
+
 static int max_probe_tries = 5;
 module_param(max_probe_tries, int, 0644);
 MODULE_PARM_DESC(max_probe_tries,
@@ -1331,7 +1337,8 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 
        /* just to be sure */
        sdata->u.mgd.flags &= ~(IEEE80211_STA_CONNECTION_POLL |
-                               IEEE80211_STA_BEACON_POLL);
+                               IEEE80211_STA_BEACON_POLL |
+                               IEEE80211_STA_RESUME_POLL);
 
        ieee80211_led_assoc(local, 1);
 
@@ -1495,11 +1502,13 @@ static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
 
        if (!(ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
-                             IEEE80211_STA_CONNECTION_POLL)))
+                             IEEE80211_STA_CONNECTION_POLL |
+                             IEEE80211_STA_RESUME_POLL)))
            return;
 
        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
-                         IEEE80211_STA_BEACON_POLL);
+                         IEEE80211_STA_BEACON_POLL |
+                         IEEE80211_STA_RESUME_POLL);
        mutex_lock(&sdata->local->iflist_mtx);
        ieee80211_recalc_ps(sdata->local, -1);
        mutex_unlock(&sdata->local->iflist_mtx);
@@ -2639,7 +2648,8 @@ static void ieee80211_sta_connection_lost(struct ieee80211_sub_if_data *sdata,
        u8 frame_buf[DEAUTH_DISASSOC_LEN];
 
        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
-                         IEEE80211_STA_BEACON_POLL);
+                         IEEE80211_STA_BEACON_POLL |
+                         IEEE80211_STA_RESUME_POLL);
 
        ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH, reason,
                               false, frame_buf);
@@ -2797,16 +2807,20 @@ void ieee80211_sta_work(struct ieee80211_sub_if_data *sdata)
                run_again(ifmgd, ifmgd->assoc_data->timeout);
 
        if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
-                           IEEE80211_STA_CONNECTION_POLL) &&
+                           IEEE80211_STA_CONNECTION_POLL |
+                           IEEE80211_STA_RESUME_POLL) &&
            ifmgd->associated) {
                u8 bssid[ETH_ALEN];
                int max_tries;
 
                memcpy(bssid, ifmgd->associated->bssid, ETH_ALEN);
 
-               if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
-                       max_tries = max_nullfunc_tries;
-               else
+               if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
+                       if (ifmgd->flags & IEEE80211_STA_RESUME_POLL)
+                               max_tries = max_nullfunc_tries_resume;
+                       else
+                               max_tries = max_nullfunc_tries;
+               } else
                        max_tries = max_probe_tries;
 
                /* ACK received for nullfunc probing frame */
@@ -2918,7 +2932,8 @@ static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
 
        if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                sdata->u.mgd.flags &= ~(IEEE80211_STA_BEACON_POLL |
-                                       IEEE80211_STA_CONNECTION_POLL);
+                                       IEEE80211_STA_CONNECTION_POLL |
+                                       IEEE80211_STA_RESUME_POLL);
 
                /* let's probe the connection once */
                flags = sdata->local->hw.flags;
@@ -2988,6 +3003,8 @@ void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata)
                add_timer(&ifmgd->chswitch_timer);
        ieee80211_sta_reset_beacon_monitor(sdata);
        ieee80211_restart_sta_timer(sdata);
+       ifmgd->flags |= IEEE80211_STA_RESUME_POLL;
+       ieee80211_queue_work(&sdata->local->hw, &sdata->u.mgd.monitor_work);
 }
 #endif