[dpdk-stable] patch 'net/bnxt: fix Rx handling and buffer allocation logic' has been queued to stable release 17.08.1

[Yuanhan Liu <yliu@fridaylinux.org>]

Hi,

FYI, your patch has been queued to stable release 17.08.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/24/17. So please
shout if anyone has objections.

Thanks.

	--yliu

---
>From ee754a2f84951da46c4a484a7f11751847172a76 Mon Sep 17 00:00:00 2001
From: Ajit Khaparde <ajit.khaparde@broadcom.com>
Date: Thu, 28 Sep 2017 16:43:27 -0500
Subject: [PATCH] net/bnxt: fix Rx handling and buffer allocation logic

[ upstream commit d9dd0b29ed315cff166b96cea278d0bcf489cd47 ]

Even when rx buffer allocation fails, we are wrongly updating
the producer index. This patch fixes that.
Also in case of a buffer allocation failure, reattempt buffer
allocation before the rx handler exits.

Fixes: 2eb53b134aae ("net/bnxt: add initial Rx code")

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
---
 drivers/net/bnxt/bnxt_rxr.c | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_rxr.c b/drivers/net/bnxt/bnxt_rxr.c
index bee67d3..bf9f78a 100644
--- a/drivers/net/bnxt/bnxt_rxr.c
+++ b/drivers/net/bnxt/bnxt_rxr.c
@@ -391,7 +391,7 @@ static int bnxt_rx_pkt(struct rte_mbuf **rx_pkt,
 	rte_prefetch0(mbuf);
 
 	if (mbuf == NULL)
-		return -ENOMEM;
+		return -EBUSY;
 
 	mbuf->nb_segs = 1;
 	mbuf->next = NULL;
@@ -448,13 +448,14 @@ static int bnxt_rx_pkt(struct rte_mbuf **rx_pkt,
 	if (bnxt_alloc_rx_data(rxq, rxr, prod)) {
 		RTE_LOG(ERR, PMD, "mbuf alloc failed with prod=0x%x\n", prod);
 		rc = -ENOMEM;
+		goto rx;
 	}
 	rxr->rx_prod = prod;
 	/*
 	 * All MBUFs are allocated with the same size under DPDK,
 	 * no optimization for rx_copy_thresh
 	 */
-
+rx:
 	*rx_pkt = mbuf;
 
 next_rx:
@@ -476,6 +477,7 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 	struct rx_pkt_cmpl *rxcmp;
 	uint16_t prod = rxr->rx_prod;
 	uint16_t ag_prod = rxr->ag_prod;
+	int rc = 0;
 
 	/* Handle RX burst request */
 	while (1) {
@@ -491,7 +493,7 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		/* TODO: Avoid magic numbers... */
 		if ((CMP_TYPE(rxcmp) & 0x30) == 0x10) {
 			rc = bnxt_rx_pkt(&rx_pkts[nb_rx_pkts], rxq, &raw_cons);
-			if (likely(!rc))
+			if (likely(!rc) || rc == -ENOMEM)
 				nb_rx_pkts++;
 			if (rc == -EBUSY)	/* partial completion */
 				break;
@@ -514,6 +516,30 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 	B_RX_DB(rxr->rx_doorbell, rxr->rx_prod);
 	/* Ring the AGG ring DB */
 	B_RX_DB(rxr->ag_doorbell, rxr->ag_prod);
+
+	/* Attempt to alloc Rx buf in case of a previous allocation failure. */
+	if (rc == -ENOMEM) {
+		int i;
+
+		for (i = prod; i <= nb_rx_pkts;
+			i = RING_NEXT(rxr->rx_ring_struct, i)) {
+			struct bnxt_sw_rx_bd *rx_buf = &rxr->rx_buf_ring[i];
+
+			/* Buffer already allocated for this index. */
+			if (rx_buf->mbuf != NULL)
+				continue;
+
+			/* This slot is empty. Alloc buffer for Rx */
+			if (!bnxt_alloc_rx_data(rxq, rxr, i)) {
+				rxr->rx_prod = i;
+				B_RX_DB(rxr->rx_doorbell, rxr->rx_prod);
+			} else {
+				RTE_LOG(ERR, PMD, "Alloc  mbuf failed\n");
+				break;
+			}
+		}
+	}
+
 	return nb_rx_pkts;
 }
 
-- 
2.7.4