On 16-10-2025 04:37, Stephen Hemminger wrote:
The limit on number of receive descriptors should be per-device.
Discovered while looking at globally exported symbols.

Fixes: 35dc25d12792 ("net/dpaa2: warn on high Rx descriptor number")
Cc: rohit.raj@nxp.com

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/dpaa2/dpaa2_ethdev.c | 9 ++++-----
 drivers/net/dpaa2/dpaa2_ethdev.h | 1 +
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/dpaa2/dpaa2_ethdev.c b/drivers/net/dpaa2/dpaa2_ethdev.c
index 41678ce09b..32edff0554 100644
--- a/drivers/net/dpaa2/dpaa2_ethdev.c
+++ b/drivers/net/dpaa2/dpaa2_ethdev.c
@@ -79,7 +79,6 @@ bool dpaa2_enable_err_queue;
 bool dpaa2_print_parser_result;
 
 #define MAX_NB_RX_DESC		11264
-int total_nb_rx_desc;

NACK,  However, we can change it to static variable.

DPAA2 supports two methods for allocating the RX descriptors.

1. Fast memory - low-latency PEB memory - The size is limited, so we globally track the number of buffers across devices.

2. Normal memory - no limit as they are from DDR. 

This variable help in tracking that overall rx descriptor across devices are not crossing the memory limit of  MAX_NB_RX_DESC

 
 int dpaa2_valid_dev;
 struct rte_mempool *dpaa2_tx_sg_pool;
@@ -720,9 +719,9 @@ dpaa2_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	DPAA2_PMD_DEBUG("dev =%p, queue =%d, pool = %p, conf =%p",
 			dev, rx_queue_id, mb_pool, rx_conf);
 
-	total_nb_rx_desc += nb_rx_desc;
-	if (total_nb_rx_desc > MAX_NB_RX_DESC) {
-		DPAA2_PMD_WARN("Total nb_rx_desc exceeds %d limit. Please use Normal buffers",
+	priv->nb_rx_desc += nb_rx_desc;
+	if (priv->nb_rx_desc > MAX_NB_RX_DESC) {
+		DPAA2_PMD_WARN("Total nb_rx_desc exceeds %u limit. Please use Normal buffers",
 			       MAX_NB_RX_DESC);
 		DPAA2_PMD_WARN("To use Normal buffers, run 'export DPNI_NORMAL_BUF=1' before running dynamic_dpl.sh script");
 	}
@@ -1029,7 +1028,7 @@ dpaa2_dev_rx_queue_release(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	memset(&cfg, 0, sizeof(struct dpni_queue));
 	PMD_INIT_FUNC_TRACE();
 
-	total_nb_rx_desc -= dpaa2_q->nb_desc;
+	priv->nb_rx_desc -= dpaa2_q->nb_desc;
 
 	if (dpaa2_q->cgid != DPAA2_INVALID_CGID) {
 		options = DPNI_QUEUE_OPT_CLEAR_CGID;
diff --git a/drivers/net/dpaa2/dpaa2_ethdev.h b/drivers/net/dpaa2/dpaa2_ethdev.h
index ffc9ebadb8..aa3fcb9af0 100644
--- a/drivers/net/dpaa2/dpaa2_ethdev.h
+++ b/drivers/net/dpaa2/dpaa2_ethdev.h
@@ -385,6 +385,7 @@ struct dpaa2_dev_priv {
 	uint8_t num_tx_tc;
 	uint16_t qos_entries;
 	uint16_t fs_entries;
+	uint16_t nb_rx_desc;
 	uint8_t dist_queues;
 	uint8_t num_channels;
 	uint8_t en_ordered;