iwlwifi: mvm: kill INACTIVE queue state

We don't really need this state: instead of having an inactive
state where we can awaken zombie queues again if needed, just
keep them in their normal state unless a new queue is actually
needed and there's no other way of getting one.

We do this here by making the inactivity check not free queues
unless instructed that we now really need to allocate one to a
specific station, and in that case it'll just free the queue
immediately, without doing any inactivity step inbetween.

The only downside is a little bit more processing in this case,
but the code complexity is lower.

Additionally, this fixes a corner case: due to the way the code
worked, we could only ever reuse an inactive queue if it was
the reserved queue for a station, as iwl_mvm_find_free_queue()
would never consider returning an inactive queue.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/mvm.h

@@ -754,19 +754,12 @@ iwl_mvm_baid_data_from_reorder_buf(struct iwl_mvm_reorder_buffer *buf)
  *	This is a state in which a single queue serves more than one TID, all of
  *	which are not aggregated. Note that the queue is only associated to one
  *	RA.
- * @IWL_MVM_QUEUE_INACTIVE: queue is allocated but no traffic on it
- *	This is a state of a queue that has had traffic on it, but during the
- *	last %IWL_MVM_DQA_QUEUE_TIMEOUT time period there has been no traffic on
- *	it. In this state, when a new queue is needed to be allocated but no
- *	such free queue exists, an inactive queue might be freed and given to
- *	the new RA/TID.
  */
 enum iwl_mvm_queue_status {
 	IWL_MVM_QUEUE_FREE,
 	IWL_MVM_QUEUE_RESERVED,
 	IWL_MVM_QUEUE_READY,
 	IWL_MVM_QUEUE_SHARED,
-	IWL_MVM_QUEUE_INACTIVE,
 };
 
 #define IWL_MVM_DQA_QUEUE_TIMEOUT	(5 * HZ)

drivers/net/wireless/intel/iwlwifi/mvm/sta.h

@@ -312,9 +312,6 @@ enum iwl_mvm_agg_state {
  *	Basically when next_reclaimed reaches ssn, we can tell mac80211 that
  *	we are ready to finish the Tx AGG stop / start flow.
  * @tx_time: medium time consumed by this A-MPDU
- * @is_tid_active: has this TID sent traffic in the last
- *	%IWL_MVM_DQA_QUEUE_TIMEOUT time period. If %txq_id is invalid, this
- *	field should be ignored.
  * @tpt_meas_start: time of the throughput measurements start, is reset every HZ
  * @tx_count_last: number of frames transmitted during the last second
  * @tx_count: counts the number of frames transmitted since the last reset of
@@ -332,7 +329,6 @@ struct iwl_mvm_tid_data {
 	u16 txq_id;
 	u16 ssn;
 	u16 tx_time;
-	bool is_tid_active;
 	unsigned long tpt_meas_start;
 	u32 tx_count_last;
 	u32 tx_count;

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

@@ -1140,32 +1140,16 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 	WARN_ON_ONCE(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM);
 
 	/* Check if TXQ needs to be allocated or re-activated */
-	if (unlikely(txq_id == IWL_MVM_INVALID_QUEUE ||
-		     !mvmsta->tid_data[tid].is_tid_active)) {
-		/* If TXQ needs to be allocated... */
-		if (txq_id == IWL_MVM_INVALID_QUEUE) {
-			iwl_mvm_tx_add_stream(mvm, mvmsta, tid, skb);
+	if (unlikely(txq_id == IWL_MVM_INVALID_QUEUE)) {
+		iwl_mvm_tx_add_stream(mvm, mvmsta, tid, skb);
 
-			/*
-			 * The frame is now deferred, and the worker scheduled
-			 * will re-allocate it, so we can free it for now.
-			 */
-			iwl_trans_free_tx_cmd(mvm->trans, dev_cmd);
-			spin_unlock(&mvmsta->lock);
-			return 0;
-		}
-
-		/* queue should always be active in new TX path */
-		WARN_ON(iwl_mvm_has_new_tx_api(mvm));
-
-		/* If we are here - TXQ exists and needs to be re-activated */
-		spin_lock(&mvm->queue_info_lock);
-		mvm->queue_info[txq_id].status = IWL_MVM_QUEUE_READY;
-		mvmsta->tid_data[tid].is_tid_active = true;
-		spin_unlock(&mvm->queue_info_lock);
-
-		IWL_DEBUG_TX_QUEUES(mvm, "Re-activating queue %d for TX\n",
-				    txq_id);
+		/*
+		 * The frame is now deferred, and the worker scheduled
+		 * will re-allocate it, so we can free it for now.
+		 */
+		iwl_trans_free_tx_cmd(mvm->trans, dev_cmd);
+		spin_unlock(&mvmsta->lock);
+		return 0;
 	}
 
 	if (!iwl_mvm_has_new_tx_api(mvm)) {