wifi: mac80211: move sched-scan stop work to wiphy work

This also has the wiphy locked here then. We need to use
the _locked version of cfg80211_sched_scan_stopped() now,
which also fixes an old deadlock there.

Fixes: a05829a7 ("cfg80211: avoid holding the RTNL when calling the driver")
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

@@ -1489,7 +1489,7 @@ struct ieee80211_local {
 	int hw_scan_ies_bufsize;
 	struct cfg80211_scan_info scan_info;
 
-	struct work_struct sched_scan_stopped_work;
+	struct wiphy_work sched_scan_stopped_work;
 	struct ieee80211_sub_if_data __rcu *sched_scan_sdata;
 	struct cfg80211_sched_scan_request __rcu *sched_scan_req;
 	u8 scan_addr[ETH_ALEN];
@@ -1968,7 +1968,8 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 				       struct cfg80211_sched_scan_request *req);
 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local);
 void ieee80211_sched_scan_end(struct ieee80211_local *local);
-void ieee80211_sched_scan_stopped_work(struct work_struct *work);
+void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
+				       struct wiphy_work *work);
 
 /* off-channel/mgmt-tx */
 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local);

net/mac80211/main.c

@@ -843,8 +843,8 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 			ieee80211_dynamic_ps_disable_work);
 	timer_setup(&local->dynamic_ps_timer, ieee80211_dynamic_ps_timer, 0);
 
-	INIT_WORK(&local->sched_scan_stopped_work,
-		  ieee80211_sched_scan_stopped_work);
+	wiphy_work_init(&local->sched_scan_stopped_work,
+			ieee80211_sched_scan_stopped_work);
 
 	spin_lock_init(&local->ack_status_lock);
 	idr_init(&local->ack_status_frames);
@@ -1502,13 +1502,13 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
 
 	wiphy_lock(local->hw.wiphy);
 	wiphy_delayed_work_cancel(local->hw.wiphy, &local->roc_work);
+	wiphy_work_cancel(local->hw.wiphy, &local->sched_scan_stopped_work);
 	wiphy_work_cancel(local->hw.wiphy, &local->radar_detected_work);
 	wiphy_unlock(local->hw.wiphy);
 	rtnl_unlock();
 
 	cancel_work_sync(&local->restart_work);
 	cancel_work_sync(&local->reconfig_filter);
-	flush_work(&local->sched_scan_stopped_work);
 
 	ieee80211_clear_tx_pending(local);
 	rate_control_deinitialize(local);

net/mac80211/scan.c

@@ -1422,10 +1422,11 @@ void ieee80211_sched_scan_end(struct ieee80211_local *local)
 
 	mutex_unlock(&local->mtx);
 
-	cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
+	cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
 }
 
-void ieee80211_sched_scan_stopped_work(struct work_struct *work)
+void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
+				       struct wiphy_work *work)
 {
 	struct ieee80211_local *local =
 		container_of(work, struct ieee80211_local,
@@ -1448,6 +1449,6 @@ void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
 	if (local->in_reconfig)
 		return;
 
-	schedule_work(&local->sched_scan_stopped_work);
+	wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
 }
 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);