iwlegacy: add flush callback

Dump implementation of flush, which just wait until all TX queues
become empty.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlegacy/3945-mac.c

@@ -3474,6 +3474,7 @@ struct ieee80211_ops il3945_mac_ops = {
 	.sta_add = il3945_mac_sta_add,
 	.sta_remove = il_mac_sta_remove,
 	.tx_last_beacon = il_mac_tx_last_beacon,
+	.flush = il_mac_flush,
 };
 
 static int

drivers/net/wireless/iwlegacy/4965-mac.c

@@ -6308,6 +6308,7 @@ const struct ieee80211_ops il4965_mac_ops = {
 	.sta_remove = il_mac_sta_remove,
 	.channel_switch = il4965_mac_channel_switch,
 	.tx_last_beacon = il_mac_tx_last_beacon,
+	.flush = il_mac_flush,
 };
 
 static int

drivers/net/wireless/iwlegacy/common.c

@@ -4707,6 +4707,42 @@ il_mac_change_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 }
 EXPORT_SYMBOL(il_mac_change_interface);
 
+void
+il_mac_flush(struct ieee80211_hw *hw, bool drop)
+{
+	struct il_priv *il = hw->priv;
+	unsigned long timeout = jiffies + msecs_to_jiffies(500);
+	int i;
+
+	mutex_lock(&il->mutex);
+	D_MAC80211("enter\n");
+
+	if (il->txq == NULL)
+		goto out;
+
+	for (i = 0; i < il->hw_params.max_txq_num; i++) {
+		struct il_queue *q;
+
+		if (i == il->cmd_queue)
+			continue;
+
+		q = &il->txq[i].q;
+		if (q->read_ptr == q->write_ptr)
+			continue;
+
+		if (time_after(jiffies, timeout)) {
+			IL_ERR("Failed to flush queue %d\n", q->id);
+			break;
+		}
+
+		msleep(20);
+	}
+out:
+	D_MAC80211("leave\n");
+	mutex_unlock(&il->mutex);
+}
+EXPORT_SYMBOL(il_mac_flush);
+
 /*
  * On every watchdog tick we check (latest) time stamp. If it does not
  * change during timeout period and queue is not empty we reset firmware.

drivers/net/wireless/iwlegacy/common.h

@@ -1723,6 +1723,7 @@ void il_mac_remove_interface(struct ieee80211_hw *hw,
 			     struct ieee80211_vif *vif);
 int il_mac_change_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			    enum nl80211_iftype newtype, bool newp2p);
+void il_mac_flush(struct ieee80211_hw *hw, bool drop);
 int il_alloc_txq_mem(struct il_priv *il);
 void il_free_txq_mem(struct il_priv *il);