qcacld-3.0: Enhance htt_rx_ring_fill_n processing

Enhance htt_rx_ring_fill_n by:
- Start timer in case the function is not able to find memory to fill rx
  buffers.
- Handle case where one stream can starve the other stream by constantly
  adding to the debt.

CRs-Fixed: 2001325
Change-Id: Idff33d9c28daaf7a00334134459a3633f5ccde7c

4 files changed, 115 insertions, 76 deletions

diff --git a/core/dp/htt/htt_internal.h b/core/dp/htt/htt_internal.h
index a68405680de5..b8d427f35605 100644
--- a/core/dp/htt/htt_internal.h
+++ b/core/dp/htt/htt_internal.h
@@ -655,7 +655,7 @@ void htt_rx_dbg_rxbuf_init(struct htt_pdev_t *pdev)
 		pdev->rx_buff_recvd_err  = 0;
 		pdev->refill_retry_timer_starts = 0;
 		pdev->refill_retry_timer_calls = 0;
-
+		pdev->refill_retry_timer_doubles = 0;
 	}
 }
 
@@ -679,16 +679,21 @@ static inline int htt_display_rx_buf_debug(struct htt_pdev_t *pdev)
 					  buf[i].posted,
 					  buf[i].recved);
 		}
+
 		QDF_TRACE(QDF_MODULE_ID_TXRX, QDF_TRACE_LEVEL_ERROR,
-		"rxbuf_idx %d all_posted: %d all_recvd: %d recv_err: %d timer_starts :%d timer_calls :%d",
+		"rxbuf_idx %d all_posted: %d all_recvd: %d recv_err: %d",
 		pdev->rx_buff_index,
 		pdev->rx_buff_posted_cum,
 		pdev->rx_buff_recvd_cum,
-		pdev->rx_buff_recvd_err,
-		pdev->refill_retry_timer_starts,
-		pdev->refill_retry_timer_calls);
-
+		pdev->rx_buff_recvd_err);
 
+		QDF_TRACE(QDF_MODULE_ID_TXRX, QDF_TRACE_LEVEL_ERROR,
+		"timer kicks :%d actual  :%d restarts:%d debtors: %d fill_n: %d",
+		pdev->refill_retry_timer_starts,
+		pdev->refill_retry_timer_calls,
+		pdev->refill_retry_timer_doubles,
+		pdev->rx_buff_debt_invoked,
+		pdev->rx_buff_fill_n_invoked);
 	} else
 		return -EINVAL;
 	return 0;
diff --git a/core/dp/htt/htt_rx.c b/core/dp/htt/htt_rx.c
index a752d639a26f..26db4b2273af 100644
--- a/core/dp/htt/htt_rx.c
+++ b/core/dp/htt/htt_rx.c
@@ -410,73 +410,6 @@ htt_rx_in_ord_paddr_get(uint32_t *u32p)
 #endif /* HELIUMPLUS_PADDR64 */
 #endif /* CONFIG_HL_SUPPORT*/
 
-#ifndef CONFIG_HL_SUPPORT
-
-static int htt_rx_ring_size(struct htt_pdev_t *pdev)
-{
-	int size;
-
-	/*
-	 * It is expected that the host CPU will typically be able to service
-	 * the rx indication from one A-MPDU before the rx indication from
-	 * the subsequent A-MPDU happens, roughly 1-2 ms later.
-	 * However, the rx ring should be sized very conservatively, to
-	 * accomodate the worst reasonable delay before the host CPU services
-	 * a rx indication interrupt.
-	 * The rx ring need not be kept full of empty buffers.  In theory,
-	 * the htt host SW can dynamically track the low-water mark in the
-	 * rx ring, and dynamically adjust the level to which the rx ring
-	 * is filled with empty buffers, to dynamically meet the desired
-	 * low-water mark.
-	 * In contrast, it's difficult to resize the rx ring itself, once
-	 * it's in use.
-	 * Thus, the ring itself should be sized very conservatively, while
-	 * the degree to which the ring is filled with empty buffers should
-	 * be sized moderately conservatively.
-	 */
-	size =
-		ol_cfg_max_thruput_mbps(pdev->ctrl_pdev) *
-		1000 /* 1e6 bps/mbps / 1e3 ms per sec = 1000 */  /
-		(8 * HTT_RX_AVG_FRM_BYTES) * HTT_RX_HOST_LATENCY_MAX_MS;
-
-	if (size < HTT_RX_RING_SIZE_MIN)
-		size = HTT_RX_RING_SIZE_MIN;
-	else if (size > HTT_RX_RING_SIZE_MAX)
-		size = HTT_RX_RING_SIZE_MAX;
-
-	size = qdf_get_pwr2(size);
-	return size;
-}
-
-static int htt_rx_ring_fill_level(struct htt_pdev_t *pdev)
-{
-	int size;
-
-	size = ol_cfg_max_thruput_mbps(pdev->ctrl_pdev) *
-		1000 /* 1e6 bps/mbps / 1e3 ms per sec = 1000 */  /
-		(8 * HTT_RX_AVG_FRM_BYTES) * HTT_RX_HOST_LATENCY_WORST_LIKELY_MS;
-
-	size = qdf_get_pwr2(size);
-	/*
-	 * Make sure the fill level is at least 1 less than the ring size.
-	 * Leaving 1 element empty allows the SW to easily distinguish
-	 * between a full ring vs. an empty ring.
-	 */
-	if (size >= pdev->rx_ring.size)
-		size = pdev->rx_ring.size - 1;
-
-	return size;
-}
-
-static void htt_rx_ring_refill_retry(void *arg)
-{
-	htt_pdev_handle pdev = (htt_pdev_handle) arg;
-
-	pdev->refill_retry_timer_calls++;
-	htt_rx_msdu_buff_replenish(pdev);
-}
-#endif
-
 /* full_reorder_offload case: this function is called with lock held */
 static int htt_rx_ring_fill_n(struct htt_pdev_t *pdev, int num)
 {
@@ -484,6 +417,7 @@ static int htt_rx_ring_fill_n(struct htt_pdev_t *pdev, int num)
 	QDF_STATUS status;
 	struct htt_host_rx_desc_base *rx_desc;
 	int filled = 0;
+	int debt_served = 0;
 
 	idx = *(pdev->rx_ring.alloc_idx.vaddr);
 
@@ -578,10 +512,9 @@ moretofill:
 		filled++;
 		idx &= pdev->rx_ring.size_mask;
 	}
-	if (qdf_atomic_read(&pdev->rx_ring.refill_debt) > 0) {
+	if (debt_served <  qdf_atomic_read(&pdev->rx_ring.refill_debt)) {
 		num = qdf_atomic_read(&pdev->rx_ring.refill_debt);
-		/* Ideally the following gives 0, but sub is safer */
-		qdf_atomic_sub(num, &pdev->rx_ring.refill_debt);
+		debt_served += num;
 		goto moretofill;
 	}
 
@@ -592,6 +525,94 @@ fail:
 	return filled;
 }
 
+
+#ifndef CONFIG_HL_SUPPORT
+
+static int htt_rx_ring_size(struct htt_pdev_t *pdev)
+{
+	int size;
+
+	/*
+	 * It is expected that the host CPU will typically be able to service
+	 * the rx indication from one A-MPDU before the rx indication from
+	 * the subsequent A-MPDU happens, roughly 1-2 ms later.
+	 * However, the rx ring should be sized very conservatively, to
+	 * accommodate the worst reasonable delay before the host CPU services
+	 * a rx indication interrupt.
+	 * The rx ring need not be kept full of empty buffers.  In theory,
+	 * the htt host SW can dynamically track the low-water mark in the
+	 * rx ring, and dynamically adjust the level to which the rx ring
+	 * is filled with empty buffers, to dynamically meet the desired
+	 * low-water mark.
+	 * In contrast, it's difficult to resize the rx ring itself, once
+	 * it's in use.
+	 * Thus, the ring itself should be sized very conservatively, while
+	 * the degree to which the ring is filled with empty buffers should
+	 * be sized moderately conservatively.
+	 */
+	size =
+		ol_cfg_max_thruput_mbps(pdev->ctrl_pdev) *
+		1000 /* 1e6 bps/mbps / 1e3 ms per sec = 1000 */  /
+		(8 * HTT_RX_AVG_FRM_BYTES) * HTT_RX_HOST_LATENCY_MAX_MS;
+
+	if (size < HTT_RX_RING_SIZE_MIN)
+		size = HTT_RX_RING_SIZE_MIN;
+	else if (size > HTT_RX_RING_SIZE_MAX)
+		size = HTT_RX_RING_SIZE_MAX;
+
+	size = qdf_get_pwr2(size);
+	return size;
+}
+
+static int htt_rx_ring_fill_level(struct htt_pdev_t *pdev)
+{
+	int size;
+
+	size = ol_cfg_max_thruput_mbps(pdev->ctrl_pdev) *
+		1000 /* 1e6 bps/mbps / 1e3 ms per sec = 1000 */  /
+		(8 * HTT_RX_AVG_FRM_BYTES) *
+		HTT_RX_HOST_LATENCY_WORST_LIKELY_MS;
+
+	size = qdf_get_pwr2(size);
+	/*
+	 * Make sure the fill level is at least 1 less than the ring size.
+	 * Leaving 1 element empty allows the SW to easily distinguish
+	 * between a full ring vs. an empty ring.
+	 */
+	if (size >= pdev->rx_ring.size)
+		size = pdev->rx_ring.size - 1;
+
+	return size;
+}
+
+static void htt_rx_ring_refill_retry(void *arg)
+{
+	htt_pdev_handle pdev = (htt_pdev_handle) arg;
+	int             filled = 0;
+	int             num;
+
+	pdev->refill_retry_timer_calls++;
+	qdf_spin_lock_bh(&(pdev->rx_ring.refill_lock));
+
+	num = qdf_atomic_read(&pdev->rx_ring.refill_debt);
+	qdf_atomic_sub(num, &pdev->rx_ring.refill_debt);
+	filled = htt_rx_ring_fill_n(pdev, num);
+
+	qdf_spin_unlock_bh(&(pdev->rx_ring.refill_lock));
+
+	if (filled > num) {
+		/* we served ourselves and some other debt */
+		/* sub is safer than  = 0 */
+		qdf_atomic_sub(filled - num, &pdev->rx_ring.refill_debt);
+	} else if (num == filled) { /* nothing to be done */
+	} else {
+		/* we could not fill all, timer must have been started */
+		pdev->refill_retry_timer_doubles++;
+	}
+
+}
+#endif
+
 static inline unsigned htt_rx_ring_elems(struct htt_pdev_t *pdev)
 {
 	return
@@ -2898,6 +2919,7 @@ int htt_rx_msdu_buff_in_order_replenish(htt_pdev_handle pdev, uint32_t num)
 		if (qdf_atomic_read(&pdev->rx_ring.refill_debt)
 			 < RX_RING_REFILL_DEBT_MAX) {
 			qdf_atomic_add(num, &pdev->rx_ring.refill_debt);
+			pdev->rx_buff_debt_invoked++;
 			return filled; /* 0 */
 		}
 		/*
@@ -2908,9 +2930,17 @@ int htt_rx_msdu_buff_in_order_replenish(htt_pdev_handle pdev, uint32_t num)
 		 */
 		qdf_spin_lock_bh(&(pdev->rx_ring.refill_lock));
 	}
+	pdev->rx_buff_fill_n_invoked++;
 	filled = htt_rx_ring_fill_n(pdev, num);
+
 	qdf_spin_unlock_bh(&(pdev->rx_ring.refill_lock));
 
+	if (filled > num) {
+		/* we served ourselves and some other debt */
+		/* sub is safer than  = 0 */
+		qdf_atomic_sub(filled - num, &pdev->rx_ring.refill_debt);
+	}
+
 	return filled;
 }
 
diff --git a/core/dp/htt/htt_types.h b/core/dp/htt/htt_types.h
index 866b42a57b29..caa0ca455347 100644
--- a/core/dp/htt/htt_types.h
+++ b/core/dp/htt/htt_types.h
@@ -418,8 +418,11 @@ struct htt_pdev_t {
 	int rx_buff_posted_cum;
 	int rx_buff_recvd_cum;
 	int rx_buff_recvd_err;
+	int rx_buff_debt_invoked;
+	int rx_buff_fill_n_invoked;
 	int refill_retry_timer_starts;
 	int refill_retry_timer_calls;
+	int refill_retry_timer_doubles;
 #endif
 
 	/* callback function for packetdump */
diff --git a/core/hdd/src/wlan_hdd_main.c b/core/hdd/src/wlan_hdd_main.c
index 7eafacf5b973..5ac1a966e02d 100644
--- a/core/hdd/src/wlan_hdd_main.c
+++ b/core/hdd/src/wlan_hdd_main.c
@@ -5706,6 +5706,7 @@ void wlan_hdd_display_tx_rx_histogram(hdd_context_t *hdd_ctx)
 					hdd_ctx->hdd_txrx_hist[i].
 						next_tx_level));
 	}
+
 	return;
 }