wifi: ath12k: flush all packets before suspend

In order to send out all packets before going to suspend, current code
adds a 500ms delay as a workaround. It is a rough estimate and may not
work.

Fix this by checking packet counters, if counters become zero, then all
packets are sent out or dropped.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4
Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240412060620.27519-7-quic_bqiang@quicinc.com

drivers/net/wireless/ath/ath12k/core.c

@@ -44,15 +44,25 @@ static int ath12k_core_rfkill_config(struct ath12k_base *ab)
 
 int ath12k_core_suspend(struct ath12k_base *ab)
 {
-	int ret;
+	struct ath12k *ar;
+	int ret, i;
 
 	if (!ab->hw_params->supports_suspend)
 		return -EOPNOTSUPP;
 
-	/* TODO: there can frames in queues so for now add delay as a hack.
-	 * Need to implement to handle and remove this delay.
-	 */
-	msleep(500);
+	rcu_read_lock();
+	for (i = 0; i < ab->num_radios; i++) {
+		ar = ath12k_mac_get_ar_by_pdev_id(ab, i);
+		if (!ar)
+			continue;
+		ret = ath12k_mac_wait_tx_complete(ar);
+		if (ret) {
+			ath12k_warn(ab, "failed to wait tx complete: %d\n", ret);
+			rcu_read_unlock();
+			return ret;
+		}
+	}
+	rcu_read_unlock();
 
 	ret = ath12k_dp_rx_pktlog_stop(ab, true);
 	if (ret) {

drivers/net/wireless/ath/ath12k/mac.c

@@ -7417,22 +7417,38 @@ static int ath12k_mac_op_set_frag_threshold(struct ieee80211_hw *hw, u32 value)
 	return -EOPNOTSUPP;
 }
 
-static void ath12k_mac_flush(struct ath12k *ar)
+static int ath12k_mac_flush(struct ath12k *ar)
 {
 	long time_left;
+	int ret = 0;
 
 	time_left = wait_event_timeout(ar->dp.tx_empty_waitq,
 				       (atomic_read(&ar->dp.num_tx_pending) == 0),
 				       ATH12K_FLUSH_TIMEOUT);
-	if (time_left == 0)
-		ath12k_warn(ar->ab, "failed to flush transmit queue %ld\n", time_left);
+	if (time_left == 0) {
+		ath12k_warn(ar->ab,
+			    "failed to flush transmit queue, data pkts pending %d\n",
+			    atomic_read(&ar->dp.num_tx_pending));
+		ret = -ETIMEDOUT;
+	}
 
 	time_left = wait_event_timeout(ar->txmgmt_empty_waitq,
 				       (atomic_read(&ar->num_pending_mgmt_tx) == 0),
 				       ATH12K_FLUSH_TIMEOUT);
-	if (time_left == 0)
-		ath12k_warn(ar->ab, "failed to flush mgmt transmit queue %ld\n",
-			    time_left);
+	if (time_left == 0) {
+		ath12k_warn(ar->ab,
+			    "failed to flush mgmt transmit queue, mgmt pkts pending %d\n",
+			    atomic_read(&ar->num_pending_mgmt_tx));
+		ret = -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
+int ath12k_mac_wait_tx_complete(struct ath12k *ar)
+{
+	ath12k_mac_drain_tx(ar);
+	return ath12k_mac_flush(ar);
 }
 
 static void ath12k_mac_op_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif,

drivers/net/wireless/ath/ath12k/mac.h

@@ -78,4 +78,5 @@ enum ath12k_supported_bw ath12k_mac_mac80211_bw_to_ath12k_bw(enum rate_info_bw b
 enum hal_encrypt_type ath12k_dp_tx_get_encrypt_type(u32 cipher);
 int ath12k_mac_rfkill_enable_radio(struct ath12k *ar, bool enable);
 int ath12k_mac_rfkill_config(struct ath12k *ar);
+int ath12k_mac_wait_tx_complete(struct ath12k *ar);
 #endif