mac80211: disable power save when scanning

[linux-2.6-omap-h63xx.git] / net / mac80211 / scan.c

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 46f35dc6accb76066873bb1dd621bf8701775c2f..3bf9839f59169cda1ded90dd8263fc3e6597097d 100644 (file)
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -214,6 +214,66 @@ void ieee80211_scan_failed(struct ieee80211_local *local)
        local->scan_req = NULL;
 }
 
+/*
+ * inform AP that we will go to sleep so that it will buffer the frames
+ * while we scan
+ */
+static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
+{
+       struct ieee80211_local *local = sdata->local;
+       bool ps = false;
+
+       /* FIXME: what to do when local->pspolling is true? */
+
+       del_timer_sync(&local->dynamic_ps_timer);
+       cancel_work_sync(&local->dynamic_ps_enable_work);
+
+       if (local->hw.conf.flags & IEEE80211_CONF_PS) {
+               ps = true;
+               local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+               ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+       }
+
+       if (!ps || !(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
+                * hardware is creating the nullfunc frame for power save
+                * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
+                * enabled) and power save was enabled, the firmware just
+                * sent a null frame with power save disabled. So we need
+                * to send a new nullfunc frame to inform the AP that we
+                * are again sleeping.
+                */
+               ieee80211_send_nullfunc(local, sdata, 1);
+}
+
+/* inform AP that we are awake again, unless power save is enabled */
+static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
+{
+       struct ieee80211_local *local = sdata->local;
+
+       if (!local->powersave)
+               ieee80211_send_nullfunc(local, sdata, 0);
+       else {
+               /*
+                * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
+                * will send a nullfunc frame with the powersave bit set
+                * even though the AP already knows that we are sleeping.
+                * This could be avoided by sending a null frame with power
+                * save bit disabled before enabling the power save, but
+                * this doesn't gain anything.
+                *
+                * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
+                * to send a nullfunc frame because AP already knows that
+                * we are sleeping, let's just enable power save mode in
+                * hardware.
+                */
+               local->hw.conf.flags |= IEEE80211_CONF_PS;
+               ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+       }
+}
+
 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 {
        struct ieee80211_local *local = hw_to_local(hw);
@@ -268,7 +328,7 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
                /* Tell AP we're back */
                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                        if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
-                               ieee80211_send_nullfunc(local, sdata, 0);
+                               ieee80211_scan_ps_disable(sdata);
                                netif_tx_wake_all_queues(sdata->dev);
                        }
                } else
@@ -441,7 +501,7 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
                        if (sdata->u.mgd.flags & IEEE80211_STA_ASSOCIATED) {
                                netif_tx_stop_all_queues(sdata->dev);
-                               ieee80211_send_nullfunc(local, sdata, 1);
+                               ieee80211_scan_ps_enable(sdata);
                        }
                } else
                        netif_tx_stop_all_queues(sdata->dev);