mac80211: extend/document powersave API

This modifies hardware flags for powersave to support three different
flags:
 * IEEE80211_HW_SUPPORTS_PS - indicates general PS support
 * IEEE80211_HW_PS_NULLFUNC_STACK - indicates nullfunc sending in software
 * IEEE80211_HW_SUPPORTS_DYNAMIC_PS - indicates dynamic PS on the device

It also adds documentation for all this which explains how to set the
various flags.

Additionally, it fixes a few things:
 * a spot where && was used to test flags
 * enable CONF_PS only when associated again

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 40 insertions, 33 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7709e7645671..a1e683e305f0 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -775,17 +775,17 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 	bss_info_changed |= BSS_CHANGED_BASIC_RATES;
 	ieee80211_bss_info_change_notify(sdata, bss_info_changed);
 
-	if (local->powersave &&
-			!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS)) {
-		if (local->hw.conf.dynamic_ps_timeout > 0)
+	if (local->powersave) {
+		if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS) &&
+		    local->hw.conf.dynamic_ps_timeout > 0) {
 			mod_timer(&local->dynamic_ps_timer, jiffies +
 				  msecs_to_jiffies(
 					local->hw.conf.dynamic_ps_timeout));
-		else {
-			ieee80211_send_nullfunc(local, sdata, 1);
+		} else {
+			if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+				ieee80211_send_nullfunc(local, sdata, 1);
 			conf->flags |= IEEE80211_CONF_PS;
-			ieee80211_hw_config(local,
-					    IEEE80211_CONF_CHANGE_PS);
+			ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 		}
 	}
 
@@ -1779,16 +1779,14 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 	ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
 				 elems.wmm_param_len);
 
-	if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS)) {
+	if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK &&
+	    local->hw.conf.flags & IEEE80211_CONF_PS) {
 		directed_tim = check_tim(&elems, ifsta->aid, &is_mc);
 
 		if (directed_tim || is_mc) {
-			if (local->hw.conf.flags && IEEE80211_CONF_PS) {
-				local->hw.conf.flags &= ~IEEE80211_CONF_PS;
-				ieee80211_hw_config(local,
-						IEEE80211_CONF_CHANGE_PS);
-				ieee80211_send_nullfunc(local, sdata, 0);
-			}
+			local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+			ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+			ieee80211_send_nullfunc(local, sdata, 0);
 		}
 	}
 
@@ -2694,9 +2692,10 @@ void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
 	if (local->hw.conf.flags & IEEE80211_CONF_PS)
 		return;
 
-	ieee80211_send_nullfunc(local, sdata, 1);
-	local->hw.conf.flags |= IEEE80211_CONF_PS;
+	if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+		ieee80211_send_nullfunc(local, sdata, 1);
 
+	local->hw.conf.flags |= IEEE80211_CONF_PS;
 	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 }
 
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index b18a72690119..cd6bc87eec73 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1295,7 +1295,7 @@ int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		return 0;
 	}
 
-	if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) &&
+	if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
 	    local->hw.conf.dynamic_ps_timeout > 0) {
 		if (local->hw.conf.flags & IEEE80211_CONF_PS) {
 			ieee80211_stop_queues_by_reason(&local->hw,
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index 3f2db0bda46c..1e5b29bdb3a7 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -837,6 +837,9 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev,
 	int ret = 0, timeout = 0;
 	bool ps;
 
+	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
+		return -EOPNOTSUPP;
+
 	if (sdata->vif.type != NL80211_IFTYPE_STATION)
 		return -EINVAL;
 
@@ -862,32 +865,37 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev,
 	if (wrq->flags & IW_POWER_TIMEOUT)
 		timeout = wrq->value / 1000;
 
-set:
+ set:
 	if (ps == local->powersave && timeout == conf->dynamic_ps_timeout)
 		return ret;
 
 	local->powersave = ps;
 	conf->dynamic_ps_timeout = timeout;
 
-	if (local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) {
+	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
 		ret = ieee80211_hw_config(local,
 					  IEEE80211_CONF_CHANGE_DYNPS_TIMEOUT);
-	} else if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
-		if (conf->dynamic_ps_timeout > 0)
-			mod_timer(&local->dynamic_ps_timer, jiffies +
-				  msecs_to_jiffies(conf->dynamic_ps_timeout));
-		else {
-			if (local->powersave) {
+
+	if (!(sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED))
+		return ret;
+
+	if (conf->dynamic_ps_timeout > 0 &&
+	    !(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)) {
+		mod_timer(&local->dynamic_ps_timer, jiffies +
+			  msecs_to_jiffies(conf->dynamic_ps_timeout));
+	} else {
+		if (local->powersave) {
+			if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
 				ieee80211_send_nullfunc(local, sdata, 1);
-				conf->flags |= IEEE80211_CONF_PS;
-				ret = ieee80211_hw_config(local,
-						IEEE80211_CONF_CHANGE_PS);
-			} else {
-				conf->flags &= ~IEEE80211_CONF_PS;
-				ret = ieee80211_hw_config(local,
-						IEEE80211_CONF_CHANGE_PS);
+			conf->flags |= IEEE80211_CONF_PS;
+			ret = ieee80211_hw_config(local,
+					IEEE80211_CONF_CHANGE_PS);
+		} else {
+			conf->flags &= ~IEEE80211_CONF_PS;
+			ret = ieee80211_hw_config(local,
+					IEEE80211_CONF_CHANGE_PS);
+			if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
 				ieee80211_send_nullfunc(local, sdata, 0);
-			}
 		}
 	}