[v2] mac80211: Fix dynamic power save for scanning.

Commit Message

Vivek Natarajan Nov. 30, 2009, 11:20 a.m. UTC

None

Patch

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 785df97..ea26afa 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -746,6 +746,7 @@  struct ieee80211_local {
 	unsigned int wmm_acm; /* bit field of ACM bits (BIT(802.1D tag)) */
 
 	bool pspolling;
+	bool scan_ps_enabled;
 	/*
 	 * PS can only be enabled when we have exactly one managed
 	 * interface (and monitors) in PS, this then points there.
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 6fad9c8..bbf8bf9 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -227,7 +227,8 @@  static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_local *local = sdata->local;
-	bool ps = false;
+
+	local->scan_ps_enabled = false;
 
 	/* FIXME: what to do when local->pspolling is true? */
 
@@ -235,12 +236,13 @@  static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
 	cancel_work_sync(&local->dynamic_ps_enable_work);
 
 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
-		ps = true;
+		local->scan_ps_enabled = 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 (!(local->scan_ps_enabled) ||
+	    !(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
@@ -261,7 +263,7 @@  static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
 
 	if (!local->ps_sdata)
 		ieee80211_send_nullfunc(local, sdata, 0);
-	else {
+	else if (local->scan_ps_enabled) {
 		/*
 		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
 		 * will send a nullfunc frame with the powersave bit set
@@ -277,6 +279,16 @@  static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
 		 */
 		local->hw.conf.flags |= IEEE80211_CONF_PS;
 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
+		/*
+		 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
+		 * had been running before leaving the operating channel,
+		 * restart the timer now and send a nullfunc frame to inform
+		 * the AP that we are awake.
+		 */
+		ieee80211_send_nullfunc(local, sdata, 0);
+		mod_timer(&local->dynamic_ps_timer, jiffies +
+			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
 	}
 }