iwlwifi: mvm: use shorter queues for mgmt and auxilary queues

In 22000 devices, aka gen2, the TFS is 256 bytes.
In order to save memory, use shorter TX queue for aux and
mgmt queues, since there isn't much traffic on them.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/fw/api/txq.h

@@ -132,6 +132,7 @@ enum iwl_tx_queue_cfg_actions {
 };
 
 #define IWL_DEFAULT_QUEUE_SIZE 256
+#define IWL_MGMT_QUEUE_SIZE 16
 /**
  * struct iwl_tx_queue_cfg_cmd - txq hw scheduler config command
  * @sta_id: station id

drivers/net/wireless/intel/iwlwifi/mvm/utils.c

@@ -728,13 +728,14 @@ int iwl_mvm_tvqm_enable_txq(struct iwl_mvm *mvm, int mac80211_queue,
 		.sta_id = sta_id,
 		.tid = tid,
 	};
-	int queue;
+	int queue, size = IWL_DEFAULT_QUEUE_SIZE;
 
-	if (cmd.tid == IWL_MAX_TID_COUNT)
+	if (cmd.tid == IWL_MAX_TID_COUNT) {
 		cmd.tid = IWL_MGMT_TID;
+		size = IWL_MGMT_QUEUE_SIZE;
+	}
 	queue = iwl_trans_txq_alloc(mvm->trans, (void *)&cmd,
-				    SCD_QUEUE_CFG, IWL_DEFAULT_QUEUE_SIZE,
-				    timeout);
+				    SCD_QUEUE_CFG, size, timeout);
 
 	if (queue < 0) {
 		IWL_DEBUG_TX_QUEUES(mvm,