mac80211: Don't wake up from PS for offchannel TX

Otherwise the offchannel frame might be queued due to
IEEE80211_QUEUE_STOP_REASON_PS and later dropped (in
ieee80211_tx_frags()).  Anyway, it doesn't make much sense to wake up
the device during ROC.
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/tx.c

@@ -214,6 +214,7 @@ ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
 {
 	struct ieee80211_local *local = tx->local;
 	struct ieee80211_if_managed *ifmgd;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 
 	/* driver doesn't support power save */
 	if (!ieee80211_hw_check(&local->hw, SUPPORTS_PS))
@@ -242,6 +243,9 @@ ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
 		return TX_CONTINUE;
 
+	if (unlikely(info->flags & IEEE80211_TX_INTFL_OFFCHAN_TX_OK))
+		return TX_CONTINUE;
+
 	ifmgd = &tx->sdata->u.mgd;
 
 	/*