iwlwifi: mvm: Configure agg. queue before assigning it to STA

In order to imeplement the extended VI session feature for Miracast, the FW
requires to detect the VI queue. The detection of the VI queue is done when
it is assigned to a STA with ADD_STA command, so by this time the FW expects
the queue to be already configured (mapped to VI AC and aggregation enabled).
Previously, the queue configuration was done after STA modificaton which
broke the extended VI session feature and resulted in higher latencies.
Fix this by calling iwl_mvm_enable_agg_txq before station modification.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/sta.c

@@ -5,8 +5,8 @@
  *
  * GPL LICENSE SUMMARY
  *
- * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2012 - 2015 Intel Corporation. All rights reserved.
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -31,8 +31,8 @@
  *
  * BSD LICENSE
  *
- * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2012 - 2015 Intel Corporation. All rights reserved.
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -1000,13 +1000,13 @@ int iwl_mvm_sta_tx_agg_oper(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
 	fifo = iwl_mvm_ac_to_tx_fifo[tid_to_mac80211_ac[tid]];
 
+	iwl_mvm_enable_agg_txq(mvm, queue, fifo, mvmsta->sta_id, tid,
+			       buf_size, ssn, wdg_timeout);
+
 	ret = iwl_mvm_sta_tx_agg(mvm, sta, tid, queue, true);
 	if (ret)
 		return -EIO;
 
-	iwl_mvm_enable_agg_txq(mvm, queue, fifo, mvmsta->sta_id, tid,
-			       buf_size, ssn, wdg_timeout);
-
 	/*
 	 * Even though in theory the peer could have different
 	 * aggregation reorder buffer sizes for different sessions,