patch 'net/bnxt: fix Rx queue stats after queue stop and start' has been queued to stable release 20.11.8

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.8

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/25/23. 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.

Queued patches are on a temporary branch at:
https://github.com/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/37a8b1a6dd47c44e7dff7e5fed8830d06eba108c

Thanks.

Luca Boccassi

---
>From 37a8b1a6dd47c44e7dff7e5fed8830d06eba108c Mon Sep 17 00:00:00 2001
From: Mike Baucom <michael.baucom at broadcom.com>
Date: Wed, 1 Feb 2023 09:50:13 +0530
Subject: [PATCH] net/bnxt: fix Rx queue stats after queue stop and start

[ upstream commit 0180d3040e4a7734dc9987ff6c49ec1daedcdf8c ]

The Rx queue stats are being reported incorrectly due to a workaround
for ring counters sometimes being reported as zero.  When a queue is
stopped and started, the ring counter is reset to zero.  The workaround
interprets the zero as incorrect, and sets the reported ring count as
the previously read value (from before the queue being restared).  This
shows up as negative counters in testpmd's "show fwd stats" command.
The fix clears the prev counter for the queue when the queue is started.

Fixes: 219842b9990c ("net/bnxt: workaround spurious zero stats in Thor")

Signed-off-by: Mike Baucom <michael.baucom at broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur at broadcom.com>
Reviewed-by: Kishore Padmanabha <kishore.padmanabha at broadcom.com>
Reviewed-by: Randy Schacher <stuart.schacher at broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde at broadcom.com>
---
 drivers/net/bnxt/bnxt_rxq.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/bnxt/bnxt_rxq.c b/drivers/net/bnxt/bnxt_rxq.c
index f597f376e6..2ed1ae117f 100644
--- a/drivers/net/bnxt/bnxt_rxq.c
+++ b/drivers/net/bnxt/bnxt_rxq.c
@@ -446,6 +446,12 @@ int bnxt_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 		return -EINVAL;
 	}
 
+	/* reset the previous stats for the rx_queue since the counters
+	 * will be cleared when the queue is started.
+	 */
+	memset(&bp->prev_rx_ring_stats[rx_queue_id], 0,
+	       sizeof(struct bnxt_ring_stats));
+
 	/* Set the queue state to started here.
 	 * We check the status of the queue while posting buffer.
 	 * If queue is it started, we do not post buffers for Rx.
-- 
2.39.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-02-23 09:36:29.239122685 +0000
+++ 0024-net-bnxt-fix-Rx-queue-stats-after-queue-stop-and-sta.patch	2023-02-23 09:36:28.218169792 +0000
@@ -1 +1 @@
-From 0180d3040e4a7734dc9987ff6c49ec1daedcdf8c Mon Sep 17 00:00:00 2001
+From 37a8b1a6dd47c44e7dff7e5fed8830d06eba108c Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 0180d3040e4a7734dc9987ff6c49ec1daedcdf8c ]
+
@@ -15 +16,0 @@
-Cc: stable at dpdk.org
@@ -27 +28 @@
-index fabbbd4560..99758dd304 100644
+index f597f376e6..2ed1ae117f 100644
@@ -30 +31 @@
-@@ -471,6 +471,12 @@ int bnxt_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id)
+@@ -446,6 +446,12 @@ int bnxt_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id)