iwlwifi: pcie: add basic reference accounting

Implement the ref/unref trans ops and track both tx and
host command queues (and hold references while they
are not empty).

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 29 insertions, 5 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c
index 8a6c7a084aa1..c1c4c75026b2 100644
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -985,17 +985,31 @@ void iwl_trans_pcie_reclaim(struct iwl_trans *trans, int txq_id, int ssn,
 
 	if (iwl_queue_space(&txq->q) > txq->q.low_mark)
 		iwl_wake_queue(trans, txq);
+
+	if (q->read_ptr == q->write_ptr) {
+		IWL_DEBUG_RPM(trans, "Q %d - last tx reclaimed\n", q->id);
+		iwl_trans_pcie_unref(trans);
+	}
+
 out:
 	spin_unlock_bh(&txq->lock);
 }
 
-static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans)
+static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans,
+				      const struct iwl_host_cmd *cmd)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	int ret;
 
 	lockdep_assert_held(&trans_pcie->reg_lock);
 
+	if (!(cmd->flags & CMD_SEND_IN_IDLE) &&
+	    !trans_pcie->ref_cmd_in_flight) {
+		trans_pcie->ref_cmd_in_flight = true;
+		IWL_DEBUG_RPM(trans, "set ref_cmd_in_flight - ref\n");
+		iwl_trans_pcie_ref(trans);
+	}
+
 	if (trans_pcie->cmd_in_flight)
 		return 0;
 
@@ -1036,6 +1050,12 @@ static int iwl_pcie_clear_cmd_in_flight(struct iwl_trans *trans)
 
 	lockdep_assert_held(&trans_pcie->reg_lock);
 
+	if (trans_pcie->ref_cmd_in_flight) {
+		trans_pcie->ref_cmd_in_flight = false;
+		IWL_DEBUG_RPM(trans, "clear ref_cmd_in_flight - unref\n");
+		iwl_trans_pcie_unref(trans);
+	}
+
 	if (WARN_ON(!trans_pcie->cmd_in_flight))
 		return 0;
 
@@ -1473,7 +1493,7 @@ static int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,
 		mod_timer(&txq->stuck_timer, jiffies + trans_pcie->wd_timeout);
 
 	spin_lock_irqsave(&trans_pcie->reg_lock, flags);
-	ret = iwl_pcie_set_cmd_in_flight(trans);
+	ret = iwl_pcie_set_cmd_in_flight(trans, cmd);
 	if (ret < 0) {
 		idx = ret;
 		spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
@@ -1819,9 +1839,13 @@ int iwl_trans_pcie_tx(struct iwl_trans *trans, struct sk_buff *skb,
 	wait_write_ptr = ieee80211_has_morefrags(fc);
 
 	/* start timer if queue currently empty */
-	if (txq->need_update && q->read_ptr == q->write_ptr &&
-	    trans_pcie->wd_timeout)
-		mod_timer(&txq->stuck_timer, jiffies + trans_pcie->wd_timeout);
+	if (q->read_ptr == q->write_ptr) {
+		if (txq->need_update && trans_pcie->wd_timeout)
+			mod_timer(&txq->stuck_timer,
+				  jiffies + trans_pcie->wd_timeout);
+		IWL_DEBUG_RPM(trans, "Q: %d first tx - take ref\n", q->id);
+		iwl_trans_pcie_ref(trans);
+	}
 
 	/* Tell device the write index *just past* this latest filled TFD */
 	q->write_ptr = iwl_queue_inc_wrap(q->write_ptr);