[RFT 3/4] ath10k: wait for mgmt tx when flushing too

[Michal Kazior]

The 10.1 firmware uses WMI to Tx management frames
but ath10k_flush() didn't care. This could lead to
some frames not being sent.

Although there are no Tx completions for WMI
mangement frames it's still better to at least
wait for ath10k queue to be drained.

Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
---
 drivers/net/wireless/ath/ath10k/mac.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 9af3ed5..47b3574 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -3766,19 +3766,27 @@ static void ath10k_flush(struct ieee80211_hw *hw, u32 queues, bool drop)
 
 	mutex_lock(&ar->conf_mutex);
 
-	if (ar->state == ATH10K_STATE_WEDGED)
+	if (ar->state == ATH10K_STATE_WEDGED) {
+		ret = -EBUSY;
 		goto skip;
+	}
 
 	ret = wait_event_timeout(ar->htt.empty_tx_wq, ({
-			bool empty;
+			bool htt_empty, wmi_empty;
+			unsigned long flags;
 
 			spin_lock_bh(&ar->htt.tx_lock);
-			empty = (ar->htt.num_pending_tx == 0);
+			htt_empty = (ar->htt.num_pending_tx == 0);
 			spin_unlock_bh(&ar->htt.tx_lock);
 
+			spin_lock_irqsave(&ar->wmi_mgmt_tx_queue.lock, flags);
+			wmi_empty = skb_queue_len(&ar->wmi_mgmt_tx_queue) == 0;
+			spin_unlock_irqrestore(&ar->wmi_mgmt_tx_queue.lock,
+					       flags);
+
 			skip = (ar->state == ATH10K_STATE_WEDGED);
 
-			(empty || skip);
+			((htt_empty && wmi_empty) || skip);
 		}), ATH10K_FLUSH_TIMEOUT_HZ);
 
 	if (ret <= 0 || skip)
@@ -3787,6 +3795,11 @@ static void ath10k_flush(struct ieee80211_hw *hw, u32 queues, bool drop)
 
 skip:
 	mutex_unlock(&ar->conf_mutex);
+
+	/* empty mgmt tx queue doesn't mean mgmt tx is flushed because the last
+	 * frame still may be processed by a worker */
+	if (ret > 0)
+		cancel_work_sync(&ar->wmi_mgmt_tx_work);
 }
 
 /* TODO: Implement this function properly
-- 
1.8.5.3