[dpdk-stable] patch 'net/qede: fix Rx packet drop' has been queued to LTS release 18.11.2

[Kevin Traynor <ktraynor@redhat.com>]

Hi,

FYI, your patch has been queued to LTS release 18.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 04/24/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Kevin Traynor

---
From d3e0551d9042d4778093f9f0e7a5a1f2fa481e4c Mon Sep 17 00:00:00 2001
From: Shahed Shaikh <shshaikh@marvell.com>
Date: Tue, 12 Mar 2019 09:51:14 -0700
Subject: [PATCH] net/qede: fix Rx packet drop

[ upstream commit 3732f83a45f5ee7b45d7655a15150f665841ce53 ]

There is a corner case in which driver won't post
receive buffers when driver has processed all received packets
in single loop (i.e. hw_consumer == sw_consumer) and then
HW will start dropping packets since it did not see new receive
buffers posted.

This corner case is seen when size of Rx ring is less than or equals
Rx packet burst count for dev->rx_pkt_burst().

Fixes: 8f2312474529 ("net/qede: fix performance bottleneck in Rx path")

Signed-off-by: Shahed Shaikh <shshaikh@marvell.com>
Acked-by: Rasesh Mody <rmody@marvell.com>
---
 drivers/net/qede/qede_rxtx.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/net/qede/qede_rxtx.c b/drivers/net/qede/qede_rxtx.c
index 70c32e3fc..27bac0995 100644
--- a/drivers/net/qede/qede_rxtx.c
+++ b/drivers/net/qede/qede_rxtx.c
@@ -1421,11 +1421,4 @@ qede_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	int rx_alloc_count = 0;
 
-	hw_comp_cons = rte_le_to_cpu_16(*rxq->hw_cons_ptr);
-	sw_comp_cons = ecore_chain_get_cons_idx(&rxq->rx_comp_ring);
-
-	rte_rmb();
-
-	if (hw_comp_cons == sw_comp_cons)
-		return 0;
 
 	/* Allocate buffers that we used in previous loop */
@@ -1448,4 +1441,12 @@ qede_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	}
 
+	hw_comp_cons = rte_le_to_cpu_16(*rxq->hw_cons_ptr);
+	sw_comp_cons = ecore_chain_get_cons_idx(&rxq->rx_comp_ring);
+
+	rte_rmb();
+
+	if (hw_comp_cons == sw_comp_cons)
+		return 0;
+
 	while (sw_comp_cons != hw_comp_cons) {
 		ol_flags = 0;
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-04-16 15:34:26.029828320 +0100
+++ 0018-net-qede-fix-Rx-packet-drop.patch	2019-04-16 15:34:25.163180327 +0100
@@ -1,8 +1,10 @@
-From 3732f83a45f5ee7b45d7655a15150f665841ce53 Mon Sep 17 00:00:00 2001
+From d3e0551d9042d4778093f9f0e7a5a1f2fa481e4c Mon Sep 17 00:00:00 2001
 From: Shahed Shaikh <shshaikh@marvell.com>
 Date: Tue, 12 Mar 2019 09:51:14 -0700
 Subject: [PATCH] net/qede: fix Rx packet drop
 
+[ upstream commit 3732f83a45f5ee7b45d7655a15150f665841ce53 ]
+
 There is a corner case in which driver won't post
 receive buffers when driver has processed all received packets
 in single loop (i.e. hw_consumer == sw_consumer) and then
@@ -13,7 +15,6 @@
 Rx packet burst count for dev->rx_pkt_burst().
 
 Fixes: 8f2312474529 ("net/qede: fix performance bottleneck in Rx path")
-Cc: stable@dpdk.org
 
 Signed-off-by: Shahed Shaikh <shshaikh@marvell.com>
 Acked-by: Rasesh Mody <rmody@marvell.com>