mac80211: Determine dynamic PS timeout based on ps-qos network latency

Determine the dynamic PS timeout based on the configured ps-qos network
latency. For backwards wext compatibility, allow the dynamic PS timeout
configured by the cfg80211 to overrule the automatically determined value.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index d811e3f..2d1a2be 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -475,6 +475,7 @@
 {
 	struct ieee80211_sub_if_data *sdata, *found = NULL;
 	int count = 0;
+	int timeout;
 
 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS)) {
 		local->ps_sdata = NULL;
@@ -508,6 +509,26 @@
 		beaconint_us = ieee80211_tu_to_usec(
 					found->vif.bss_conf.beacon_int);
 
+		timeout = local->hw.conf.dynamic_ps_forced_timeout;
+		if (timeout < 0) {
+			/*
+			 * The 2 second value is there for compatibility until
+			 * the PM_QOS_NETWORK_LATENCY is configured with real
+			 * values.
+			 */
+			if (latency == 2000000000)
+				timeout = 100;
+			else if (latency <= 50000)
+				timeout = 300;
+			else if (latency <= 100000)
+				timeout = 100;
+			else if (latency <= 500000)
+				timeout = 50;
+			else
+				timeout = 0;
+		}
+		local->hw.conf.dynamic_ps_timeout = timeout;
+
 		if (beaconint_us > latency) {
 			local->ps_sdata = NULL;
 		} else {