qca-wifi: Drop excessive PPDU status buffers

When CPU cores are fully loaded, PPDU stats process workqueue
is not getting enough time, resulting in excessive backlog of
PPDU status buffers. Check and drop buffers if the backlog is
beyond a threshold.

Change-Id: Ideef46cb4eec54dcd5a8315f36f2206653d81659

dp/wifi3.0/dp_tx_capture.c

@@ -162,6 +162,8 @@ void dp_tx_ppdu_stats_attach(struct dp_pdev *pdev)
 	qdf_spinlock_create(&pdev->tx_capture.ppdu_stats_lock);
 	pdev->tx_capture.ppdu_stats_queue_depth = 0;
 	pdev->tx_capture.ppdu_stats_next_sched = 0;
+	pdev->tx_capture.ppdu_stats_defer_queue_depth = 0;
+	pdev->tx_capture.ppdu_dropped = 0;
 }
 
 /**
@@ -855,22 +857,23 @@ uint32_t dp_tx_msdu_dequeue(struct dp_peer *peer, uint32_t ppdu_id,
 
 		wbm_tsf = ptr_msdu_info->tsf;
 
+		if (wbm_tsf < start_tsf) {
+			/* remove the aged packet */
+			nbuf = qdf_nbuf_queue_remove(
+					&tx_tid->msdu_comp_q);
+
+			qdf_nbuf_free(nbuf);
+
+			curr_msdu = qdf_nbuf_queue_first(
+					&tx_tid->msdu_comp_q);
+			prev_msdu = NULL;
+			continue;
+		}
 		if (msdu_ppdu_id == ppdu_id) {
 			matched = 1;
 
 			if (wbm_tsf > start_tsf && wbm_tsf < end_tsf) {
 				/*packet found */
-			} else if (wbm_tsf < start_tsf) {
-				/* remove the aged packet */
-				nbuf = qdf_nbuf_queue_remove(
-						&tx_tid->msdu_comp_q);
-
-				qdf_nbuf_free(nbuf);
-
-				curr_msdu = qdf_nbuf_queue_first(
-						&tx_tid->msdu_comp_q);
-				prev_msdu = NULL;
-				continue;
 			} else if (wbm_tsf > end_tsf) {
 				/*
 				 * Do we need delta in above case.
@@ -1258,7 +1261,7 @@ QDF_STATUS dp_send_mpdu_info_to_stack(struct dp_pdev *pdev,
  * which doesn't include BAR and other non data frame
  * ~50 is maximum scheduled ppdu count
  */
-#define SCHED_MAX_PPDU_CNT 50
+#define SCHED_MAX_PPDU_CNT 64
 /**
  * dp_tx_ppdu_stats_process - Deferred PPDU stats handler
  * @context: Opaque work context (PDEV)
@@ -1286,6 +1289,8 @@ void dp_tx_ppdu_stats_process(void *context)
 	qdf_spin_lock_bh(&ptr_tx_cap->ppdu_stats_lock);
 	STAILQ_CONCAT(&ptr_tx_cap->ppdu_stats_defer_queue,
 		      &ptr_tx_cap->ppdu_stats_queue);
+	ptr_tx_cap->ppdu_stats_defer_queue_depth +=
+		ptr_tx_cap->ppdu_stats_queue_depth;
 	ptr_tx_cap->ppdu_stats_queue_depth = 0;
 	qdf_spin_unlock_bh(&ptr_tx_cap->ppdu_stats_lock);
 
@@ -1300,8 +1305,9 @@ void dp_tx_ppdu_stats_process(void *context)
 				    ppdu_info_queue_elem, tmp_ppdu_info) {
 			if (curr_sched_cmdid != ppdu_info->sched_cmdid)
 				break;
-			sched_ppdu_list[ppdu_cnt++] = ppdu_info;
-			qdf_assert_always(ppdu_cnt <= SCHED_MAX_PPDU_CNT);
+			qdf_assert_always(ppdu_cnt < SCHED_MAX_PPDU_CNT);
+			sched_ppdu_list[ppdu_cnt] = ppdu_info;
+			ppdu_cnt++;
 		}
 		if (ppdu_info && (curr_sched_cmdid == ppdu_info->sched_cmdid) &&
 		    ptr_tx_cap->ppdu_stats_next_sched < now_ms)
@@ -1311,6 +1317,7 @@ void dp_tx_ppdu_stats_process(void *context)
 		STAILQ_REMOVE_HEAD_UNTIL(&ptr_tx_cap->ppdu_stats_defer_queue,
 					 sched_ppdu_list[ppdu_cnt - 1],
 					 ppdu_info_queue_elem);
+		ptr_tx_cap->ppdu_stats_defer_queue_depth -= ppdu_cnt;
 
 		ppdu_desc_cnt = 0;
 		/* Process tx buffer list based on last_ppdu_id stored above */
@@ -1549,14 +1556,24 @@ void dp_ppdu_desc_deliver(struct dp_pdev *pdev,
 			qdf_nbuf_data(ppdu_info->nbuf);
 
 	qdf_spin_lock_bh(&pdev->tx_capture.ppdu_stats_lock);
-	STAILQ_INSERT_TAIL(&pdev->tx_capture.ppdu_stats_queue,
-			   ppdu_info, ppdu_info_queue_elem);
-	pdev->tx_capture.ppdu_stats_queue_depth++;
+
+	if (qdf_unlikely(!pdev->tx_capture_enabled &&
+	    (pdev->tx_capture.ppdu_stats_queue_depth +
+	    pdev->tx_capture.ppdu_stats_defer_queue_depth) >
+	    DP_TX_PPDU_PROC_MAX_DEPTH)) {
+		qdf_nbuf_free(ppdu_info->nbuf);
+		qdf_mem_free(ppdu_info);
+		pdev->tx_capture.ppdu_dropped++;
+	} else {
+		STAILQ_INSERT_TAIL(&pdev->tx_capture.ppdu_stats_queue,
+				   ppdu_info, ppdu_info_queue_elem);
+		pdev->tx_capture.ppdu_stats_queue_depth++;
+	}
 	qdf_spin_unlock_bh(&pdev->tx_capture.ppdu_stats_lock);
 
 	if ((pdev->tx_capture.ppdu_stats_queue_depth >
 	    DP_TX_PPDU_PROC_THRESHOLD) ||
-	    (pdev->tx_capture.ppdu_stats_next_sched > now_ms)) {
+	    (pdev->tx_capture.ppdu_stats_next_sched <= now_ms)) {
 		qdf_queue_work(0, pdev->tx_capture.ppdu_stats_workqueue,
 			       &pdev->tx_capture.ppdu_stats_work);
 		pdev->tx_capture.ppdu_stats_next_sched =

dp/wifi3.0/dp_tx_capture.h

@@ -21,6 +21,8 @@
 
 #ifdef WLAN_TX_PKT_CAPTURE_ENH
 
+#define DP_TX_PPDU_PROC_MAX_DEPTH 512
+
 struct dp_soc;
 struct dp_pdev;
 struct dp_vdev;
@@ -39,11 +41,13 @@ struct dp_pdev_tx_capture {
 	STAILQ_HEAD(, ppdu_info) ppdu_stats_defer_queue;
 
 	uint32_t ppdu_stats_queue_depth;
+	uint32_t ppdu_stats_defer_queue_depth;
 	uint32_t ppdu_stats_next_sched;
 	qdf_spinlock_t msdu_comp_q_list_lock;
 	uint32_t missed_ppdu_id;
 	uint32_t last_msdu_id;
 	qdf_event_t miss_ppdu_event;
+	uint32_t ppdu_dropped;
 };
 
 /* Tx TID */