ath11k: add wait operation for tx management packets for flush from mac80211

In ath11k, tx of management packet is doing in a work queue. Sometimes
the workqueue does not finish tx immediately, then it lead after the next
step of vdev delete finished, it start to send the management packet to
firmware and lead firmware crash.

ieee80211_set_disassoc() have logic of ieee80211_flush_queues() after
it send_deauth_disassoc() to ath11k, its purpose is make sure the
deauth was actually sent, so it need to change ath11k to match the
purpose of mac80211.

To address these issue wait for tx mgmt as well as tx data packets.

dmesg log of connect/disconnect to AP:
[  307.522226] wls1: authenticate with 62:66:e4:e9:6a:a9
[  307.586565] wls1: send auth to 62:66:e4:e9:6a:a9 (try 1/3)
[  307.586581] ath11k_pci 0000:05:00.0: mac tx mgmt frame, buf id 0
[  307.586922] ath11k_pci 0000:05:00.0: mac tx mgmt frame, vdev_id 0
[  307.590179] ath11k_pci 0000:05:00.0: wmi mgmt tx comp pending 0 desc id 0
[  307.590181] ath11k_pci 0000:05:00.0: mgmt tx compl ev pdev_id 2, desc_id 0, status 0
[  307.598699] wls1: authenticated
[  307.599483] wls1: associate with 62:66:e4:e9:6a:a9 (try 1/3)
[  307.599506] ath11k_pci 0000:05:00.0: mac tx mgmt frame, buf id 0
[  307.599519] ath11k_pci 0000:05:00.0: mac tx mgmt frame, vdev_id 0
[  307.603059] ath11k_pci 0000:05:00.0: wmi mgmt tx comp pending 0 desc id 0
[  307.603063] ath11k_pci 0000:05:00.0: mgmt tx compl ev pdev_id 2, desc_id 0, status 0
[  307.637105] wls1: associated
[  317.365239] wls1: deauthenticating from 62:66:e4:e9:6a:a9 by local choice (Reason: 3=DEAUTH_LEAVING)
[  317.368104] ath11k_pci 0000:05:00.0: mac tx mgmt frame, buf id 0
[  317.372622] ath11k_pci 0000:05:00.0: mac tx mgmt frame, vdev_id 0
[  317.378320] ath11k_pci 0000:05:00.0: wmi mgmt tx comp pending 0 desc id 0
[  317.378330] ath11k_pci 0000:05:00.0: mgmt tx compl ev pdev_id 2, desc_id 0, status 0
[  317.378359] ath11k_pci 0000:05:00.0: mac mgmt tx flush mgmt pending 0
[  317.421066] ath11k_pci 0000:05:00.0: mac mgmt tx flush mgmt pending 0
[  317.421427] ath11k_pci 0000:05:00.0: mac remove interface (vdev 0)

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01230-QCAHSTSWPLZ_V2_TO_X86-1
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20211202063705.14321-1-quic_wgong@quicinc.com

drivers/net/wireless/ath/ath11k/core.c

@@ -1165,6 +1165,7 @@ static void ath11k_core_restart(struct work_struct *work)
 		idr_for_each(&ar->txmgmt_idr,
 			     ath11k_mac_tx_mgmt_pending_free, ar);
 		idr_destroy(&ar->txmgmt_idr);
+		wake_up(&ar->txmgmt_empty_waitq);
 	}
 
 	wake_up(&ab->wmi_ab.tx_credits_wq);

drivers/net/wireless/ath/ath11k/core.h

@@ -550,6 +550,7 @@ struct ath11k {
 	/* protects txmgmt_idr data */
 	spinlock_t txmgmt_idr_lock;
 	atomic_t num_pending_mgmt_tx;
+	wait_queue_head_t txmgmt_empty_waitq;
 
 	/* cycle count is reported twice for each visited channel during scan.
 	 * access protected by data_lock

drivers/net/wireless/ath/ath11k/mac.c

@@ -5265,6 +5265,21 @@ static int __ath11k_set_antenna(struct ath11k *ar, u32 tx_ant, u32 rx_ant)
 	return 0;
 }
 
+static void ath11k_mgmt_over_wmi_tx_drop(struct ath11k *ar, struct sk_buff *skb)
+{
+	int num_mgmt;
+
+	ieee80211_free_txskb(ar->hw, skb);
+
+	num_mgmt = atomic_dec_if_positive(&ar->num_pending_mgmt_tx);
+
+	if (num_mgmt < 0)
+		WARN_ON_ONCE(1);
+
+	if (!num_mgmt)
+		wake_up(&ar->txmgmt_empty_waitq);
+}
+
 static void ath11k_mac_tx_mgmt_free(struct ath11k *ar, int buf_id)
 {
 	struct sk_buff *msdu;
@@ -5283,7 +5298,7 @@ static void ath11k_mac_tx_mgmt_free(struct ath11k *ar, int buf_id)
 	info = IEEE80211_SKB_CB(msdu);
 	memset(&info->status, 0, sizeof(info->status));
 
-	ieee80211_free_txskb(ar->hw, msdu);
+	ath11k_mgmt_over_wmi_tx_drop(ar, msdu);
 }
 
 int ath11k_mac_tx_mgmt_pending_free(int buf_id, void *skb, void *ctx)
@@ -5323,6 +5338,10 @@ static int ath11k_mac_mgmt_tx_wmi(struct ath11k *ar, struct ath11k_vif *arvif,
 	buf_id = idr_alloc(&ar->txmgmt_idr, skb, 0,
 			   ATH11K_TX_MGMT_NUM_PENDING_MAX, GFP_ATOMIC);
 	spin_unlock_bh(&ar->txmgmt_idr_lock);
+
+	ath11k_dbg(ar->ab, ATH11K_DBG_MAC,
+		   "mac tx mgmt frame, buf id %d\n", buf_id);
+
 	if (buf_id < 0)
 		return -ENOSPC;
 
@@ -5369,7 +5388,7 @@ static void ath11k_mgmt_over_wmi_tx_purge(struct ath11k *ar)
 	struct sk_buff *skb;
 
 	while ((skb = skb_dequeue(&ar->wmi_mgmt_tx_queue)) != NULL)
-		ieee80211_free_txskb(ar->hw, skb);
+		ath11k_mgmt_over_wmi_tx_drop(ar, skb);
 }
 
 static void ath11k_mgmt_over_wmi_tx_work(struct work_struct *work)
@@ -5384,29 +5403,29 @@ static void ath11k_mgmt_over_wmi_tx_work(struct work_struct *work)
 		skb_cb = ATH11K_SKB_CB(skb);
 		if (!skb_cb->vif) {
 			ath11k_warn(ar->ab, "no vif found for mgmt frame\n");
-			ieee80211_free_txskb(ar->hw, skb);
+			ath11k_mgmt_over_wmi_tx_drop(ar, skb);
 			continue;
 		}
 
 		arvif = ath11k_vif_to_arvif(skb_cb->vif);
 		if (ar->allocated_vdev_map & (1LL << arvif->vdev_id) &&
 		    arvif->is_started) {
-			atomic_inc(&ar->num_pending_mgmt_tx);
 			ret = ath11k_mac_mgmt_tx_wmi(ar, arvif, skb);
 			if (ret) {
-				if (atomic_dec_if_positive(&ar->num_pending_mgmt_tx) < 0)
-					WARN_ON_ONCE(1);
-
 				ath11k_warn(ar->ab, "failed to tx mgmt frame, vdev_id %d :%d\n",
 					    arvif->vdev_id, ret);
-				ieee80211_free_txskb(ar->hw, skb);
+				ath11k_mgmt_over_wmi_tx_drop(ar, skb);
+			} else {
+				ath11k_dbg(ar->ab, ATH11K_DBG_MAC,
+					   "mac tx mgmt frame, vdev_id %d\n",
+					   arvif->vdev_id);
 			}
 		} else {
 			ath11k_warn(ar->ab,
 				    "dropping mgmt frame for vdev %d, is_started %d\n",
 				    arvif->vdev_id,
 				    arvif->is_started);
-			ieee80211_free_txskb(ar->hw, skb);
+			ath11k_mgmt_over_wmi_tx_drop(ar, skb);
 		}
 	}
 }
@@ -5437,6 +5456,7 @@ static int ath11k_mac_mgmt_tx(struct ath11k *ar, struct sk_buff *skb,
 	}
 
 	skb_queue_tail(q, skb);
+	atomic_inc(&ar->num_pending_mgmt_tx);
 	ieee80211_queue_work(ar->hw, &ar->wmi_mgmt_tx_work);
 
 	return 0;
@@ -7023,6 +7043,17 @@ static void ath11k_mac_op_flush(struct ieee80211_hw *hw, struct ieee80211_vif *v
 				       ATH11K_FLUSH_TIMEOUT);
 	if (time_left == 0)
 		ath11k_warn(ar->ab, "failed to flush transmit queue %ld\n", time_left);
+
+	time_left = wait_event_timeout(ar->txmgmt_empty_waitq,
+				       (atomic_read(&ar->num_pending_mgmt_tx) == 0),
+				       ATH11K_FLUSH_TIMEOUT);
+	if (time_left == 0)
+		ath11k_warn(ar->ab, "failed to flush mgmt transmit queue %ld\n",
+			    time_left);
+
+	ath11k_dbg(ar->ab, ATH11K_DBG_MAC,
+		   "mac mgmt tx flush mgmt pending %d\n",
+		   atomic_read(&ar->num_pending_mgmt_tx));
 }
 
 static int
@@ -8261,6 +8292,8 @@ int ath11k_mac_register(struct ath11k_base *ab)
 		ret = __ath11k_mac_register(ar);
 		if (ret)
 			goto err_cleanup;
+
+		init_waitqueue_head(&ar->txmgmt_empty_waitq);
 	}
 
 	return 0;

drivers/net/wireless/ath/ath11k/wmi.c

@@ -4980,6 +4980,7 @@ static int wmi_process_mgmt_tx_comp(struct ath11k *ar, u32 desc_id,
 	struct sk_buff *msdu;
 	struct ieee80211_tx_info *info;
 	struct ath11k_skb_cb *skb_cb;
+	int num_mgmt;
 
 	spin_lock_bh(&ar->txmgmt_idr_lock);
 	msdu = idr_find(&ar->txmgmt_idr, desc_id);
@@ -5003,10 +5004,19 @@ static int wmi_process_mgmt_tx_comp(struct ath11k *ar, u32 desc_id,
 
 	ieee80211_tx_status_irqsafe(ar->hw, msdu);
 
+	num_mgmt = atomic_dec_if_positive(&ar->num_pending_mgmt_tx);
+
 	/* WARN when we received this event without doing any mgmt tx */
-	if (atomic_dec_if_positive(&ar->num_pending_mgmt_tx) < 0)
+	if (num_mgmt < 0)
 		WARN_ON_ONCE(1);
 
+	ath11k_dbg(ar->ab, ATH11K_DBG_WMI,
+		   "wmi mgmt tx comp pending %d desc id %d\n",
+		   num_mgmt, desc_id);
+
+	if (!num_mgmt)
+		wake_up(&ar->txmgmt_empty_waitq);
+
 	return 0;
 }