mwifiex: use LOW_PRIORITY scan flag provided in scan request

We will delay/abort scan operation based on traffic for low
priority scan.
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

@@ -1819,7 +1819,8 @@ mwifiex_cfg80211_scan(struct wiphy *wiphy,
 
 	wiphy_dbg(wiphy, "info: received scan request on %s\n", dev->name);
 
-	if (atomic_read(&priv->wmm.tx_pkts_queued) >=
+	if ((request->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
+	    atomic_read(&priv->wmm.tx_pkts_queued) >=
 	    MWIFIEX_MIN_TX_PENDING_TO_CANCEL_SCAN) {
 		dev_dbg(priv->adapter->dev, "scan rejected due to traffic\n");
 		return -EBUSY;
@@ -2251,7 +2252,8 @@ int mwifiex_register_cfg80211(struct mwifiex_adapter *adapter)
 	wiphy->available_antennas_rx = BIT(adapter->number_of_antenna) - 1;
 
 	wiphy->features |= NL80211_FEATURE_HT_IBSS |
-			   NL80211_FEATURE_INACTIVITY_TIMER;
+			   NL80211_FEATURE_INACTIVITY_TIMER |
+			   NL80211_FEATURE_LOW_PRIORITY_SCAN;
 
 	/* Reserve space for mwifiex specific private data for BSS */
 	wiphy->bss_priv_size = sizeof(struct mwifiex_bss_priv);

drivers/net/wireless/mwifiex/scan.c

@@ -1776,12 +1776,16 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
 			priv->user_scan_cfg = NULL;
 		}
 	} else {
-		if (!mwifiex_wmm_lists_empty(adapter)) {
+		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,
 					       flags);
 			adapter->scan_delay_cnt = 1;
 			mod_timer(&priv->scan_delay_timer, jiffies +
 				  msecs_to_jiffies(MWIFIEX_SCAN_DELAY_MSEC));
+			dev_dbg(priv->adapter->dev,
+				"info: %s: deferring scan\n", __func__);
 		} else {
 			/* Get scan command from scan_pending_q and put to
 			   cmd_pending_q */