mac80211: A couple of fixes to dynamic power save.

a) hw_config() should not be called from siwpower() for the drivers which do not support
   dynamic powersave.
b) IEEE80211_HW_NO_STACK_DYNAMIC_PS needs to be verified in set_associated() also before
   enabling the power save timers.
Signed-off-by: NVivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/mlme.c

@@ -751,7 +751,8 @@ 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) {
+	if (local->powersave &&
+			!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS)) {
 		if (local->dynamic_ps_timeout > 0)
 			mod_timer(&local->dynamic_ps_timer, jiffies +
 				  msecs_to_jiffies(local->dynamic_ps_timeout));

net/mac80211/wext.c

@@ -865,9 +865,9 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev,
 	local->powersave = ps;
 	local->dynamic_ps_timeout = timeout;
 
-	if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) {
-		if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) &&
-		    local->dynamic_ps_timeout > 0)
+	if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) &&
+			(sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED)) {
+		if (local->dynamic_ps_timeout > 0)
 			mod_timer(&local->dynamic_ps_timer, jiffies +
 				  msecs_to_jiffies(local->dynamic_ps_timeout));
 		else {
@@ -875,8 +875,9 @@ static int ieee80211_ioctl_siwpower(struct net_device *dev,
 				conf->flags |= IEEE80211_CONF_PS;
 			else
 				conf->flags &= ~IEEE80211_CONF_PS;
+			ret = ieee80211_hw_config(local,
+					IEEE80211_CONF_CHANGE_PS);
 		}
-		ret = ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 	}
 
 	return ret;