mac80211: purge remain-on-channel items when suspending

They can't really be executed while suspended and could
trigger work warnings, so abort all ROC items. When the
system resumes the notifications about this will be
delivered to userspace which can then act accordingly
(though it will assume they were canceled/finished.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

@@ -1315,7 +1315,8 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local);
 void ieee80211_offchannel_return(struct ieee80211_local *local);
 void ieee80211_roc_setup(struct ieee80211_local *local);
 void ieee80211_start_next_roc(struct ieee80211_local *local);
-void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata);
+void ieee80211_roc_purge(struct ieee80211_local *local,
+			 struct ieee80211_sub_if_data *sdata);
 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc);
 void ieee80211_sw_roc_work(struct work_struct *work);
 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc);

net/mac80211/iface.c

@@ -693,7 +693,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 	if (sdata->dev)
 		netif_tx_stop_all_queues(sdata->dev);
 
-	ieee80211_roc_purge(sdata);
+	ieee80211_roc_purge(local, sdata);
 
 	if (sdata->vif.type == NL80211_IFTYPE_STATION)
 		ieee80211_mgd_stop(sdata);

net/mac80211/offchannel.c

@@ -436,15 +436,15 @@ void ieee80211_roc_setup(struct ieee80211_local *local)
 	INIT_LIST_HEAD(&local->roc_list);
 }
 
-void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
+void ieee80211_roc_purge(struct ieee80211_local *local,
+			 struct ieee80211_sub_if_data *sdata)
 {
-	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_roc_work *roc, *tmp;
 	LIST_HEAD(tmp_list);
 
 	mutex_lock(&local->mtx);
 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
-		if (roc->sdata != sdata)
+		if (sdata && roc->sdata != sdata)
 			continue;
 
 		if (roc->started && local->ops->remain_on_channel) {

net/mac80211/pm.c

@@ -19,6 +19,8 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 
 	ieee80211_dfs_cac_cancel(local);
 
+	ieee80211_roc_purge(local, NULL);
+
 	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
 		mutex_lock(&local->sta_mtx);
 		list_for_each_entry(sta, &local->sta_list, list) {