mwifiex: abort scan upon interface down

When the interface is down, we will abort scan by calling
cfg80211_scan_done() with abort option. This fixes WARN_ON
triggered by cfg80211 in wdev_cleanup_work().

Driver's internal variables/flags are cleared once we get
response for current scan command. Meanwhile we will block
new scan request from cfg80211.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -1828,6 +1828,11 @@ mwifiex_cfg80211_scan(struct wiphy *wiphy,
 
 	priv->scan_request = request;
 
+	if (priv->user_scan_cfg) {
+		dev_err(priv->adapter->dev, "cmd: Scan already in process..\n");
+		return -EBUSY;
+	}
+
 	priv->user_scan_cfg = kzalloc(sizeof(struct mwifiex_user_scan_cfg),
 				      GFP_KERNEL);
 	if (!priv->user_scan_cfg) {

drivers/net/wireless/mwifiex/init.c

@@ -84,10 +84,16 @@ static void scan_delay_timer_fn(unsigned long data)
 		spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
 
 		if (priv->user_scan_cfg) {
+			if (priv->scan_request) {
 				dev_dbg(priv->adapter->dev,
-				"info: %s: scan aborted\n", __func__);
+					"info: aborting scan\n");
 				cfg80211_scan_done(priv->scan_request, 1);
 				priv->scan_request = NULL;
+			} else {
+				dev_dbg(priv->adapter->dev,
+					"info: scan already aborted\n");
+			}
+
 			kfree(priv->user_scan_cfg);
 			priv->user_scan_cfg = NULL;
 		}

drivers/net/wireless/mwifiex/main.c

@@ -472,6 +472,14 @@ mwifiex_open(struct net_device *dev)
 static int
 mwifiex_close(struct net_device *dev)
 {
+	struct mwifiex_private *priv = mwifiex_netdev_get_priv(dev);
+
+	if (priv->scan_request) {
+		dev_dbg(priv->adapter->dev, "aborting scan on ndo_stop\n");
+		cfg80211_scan_done(priv->scan_request, 1);
+		priv->scan_request = NULL;
+	}
+
 	return 0;
 }
 

drivers/net/wireless/mwifiex/scan.c

@@ -1768,15 +1768,28 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
 		}
 
 		if (priv->user_scan_cfg) {
+			if (priv->scan_request) {
 				dev_dbg(priv->adapter->dev,
-				"info: %s: sending scan results\n", __func__);
+					"info: notifying scan done\n");
 				cfg80211_scan_done(priv->scan_request, 0);
 				priv->scan_request = NULL;
+			} else {
+				dev_dbg(priv->adapter->dev,
+					"info: scan already aborted\n");
+			}
+
 			kfree(priv->user_scan_cfg);
 			priv->user_scan_cfg = NULL;
 		}
 	} else {
-		if (!mwifiex_wmm_lists_empty(adapter) &&
+		if (priv->user_scan_cfg && !priv->scan_request) {
+			spin_unlock_irqrestore(&adapter->scan_pending_q_lock,
+					       flags);
+			adapter->scan_delay_cnt = MWIFIEX_MAX_SCAN_DELAY_CNT;
+			mod_timer(&priv->scan_delay_timer, jiffies);
+			dev_dbg(priv->adapter->dev,
+				"info: %s: triggerring scan abort\n", __func__);
+		} else if (!mwifiex_wmm_lists_empty(adapter) &&
 			   (priv->scan_request && (priv->scan_request->flags &
 					    NL80211_SCAN_FLAG_LOW_PRIORITY))) {
 			spin_unlock_irqrestore(&adapter->scan_pending_q_lock,