[v2 1/1] app/testpmd: use RSS conf from software when configuring DCB

[Min Zhou <zhoumin@loongson.cn>]

In the testpmd command, we have to stop the port firstly before configuring
the DCB. However, some PMDs may execute a hardware reset during the port
stop, such as ixgbe. Some kind of reset operations of PMD could clear the
configurations of RSS in the hardware register. This would cause the loss
of RSS configurations that were set during the testpmd initialization. As
a result, I find that I cannot enable RSS and DCB at the same time in the
testpmd command when using Intel 82599 NIC.

The patch uses rss conf from software instead of reading from the hardware
register when configuring DCB.

Signed-off-by: Min Zhou <zhoumin@loongson.cn>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

---
v2:
Make internal function get_eth_dcb_conf return void and remove the unused
parameter port_id.
---

 app/test-pmd/testpmd.c | 26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index f487769578..ac654048df 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -4080,15 +4080,11 @@ const uint16_t vlan_tags[] = {
 		24, 25, 26, 27, 28, 29, 30, 31
 };
 
-static  int
-get_eth_dcb_conf(portid_t pid, struct rte_eth_conf *eth_conf,
-		 enum dcb_mode_enable dcb_mode,
-		 enum rte_eth_nb_tcs num_tcs,
-		 uint8_t pfc_en)
+static void
+get_eth_dcb_conf(struct rte_eth_conf *eth_conf, enum dcb_mode_enable dcb_mode,
+		 enum rte_eth_nb_tcs num_tcs, uint8_t pfc_en)
 {
 	uint8_t i;
-	int32_t rc;
-	struct rte_eth_rss_conf rss_conf;
 
 	/*
 	 * Builds up the correct configuration for dcb+vt based on the vlan tags array
@@ -4130,12 +4126,6 @@ get_eth_dcb_conf(portid_t pid, struct rte_eth_conf *eth_conf,
 		struct rte_eth_dcb_tx_conf *tx_conf =
 				&eth_conf->tx_adv_conf.dcb_tx_conf;
 
-		memset(&rss_conf, 0, sizeof(struct rte_eth_rss_conf));
-
-		rc = rte_eth_dev_rss_hash_conf_get(pid, &rss_conf);
-		if (rc != 0)
-			return rc;
-
 		rx_conf->nb_tcs = num_tcs;
 		tx_conf->nb_tcs = num_tcs;
 
@@ -4147,7 +4137,6 @@ get_eth_dcb_conf(portid_t pid, struct rte_eth_conf *eth_conf,
 		eth_conf->rxmode.mq_mode =
 				(enum rte_eth_rx_mq_mode)
 					(rx_mq_mode & RTE_ETH_MQ_RX_DCB_RSS);
-		eth_conf->rx_adv_conf.rss_conf = rss_conf;
 		eth_conf->txmode.mq_mode = RTE_ETH_MQ_TX_DCB;
 	}
 
@@ -4156,8 +4145,6 @@ get_eth_dcb_conf(portid_t pid, struct rte_eth_conf *eth_conf,
 				RTE_ETH_DCB_PG_SUPPORT | RTE_ETH_DCB_PFC_SUPPORT;
 	else
 		eth_conf->dcb_capability_en = RTE_ETH_DCB_PG_SUPPORT;
-
-	return 0;
 }
 
 int
@@ -4180,10 +4167,9 @@ init_port_dcb_config(portid_t pid,
 	/* retain the original device configuration. */
 	memcpy(&port_conf, &rte_port->dev_conf, sizeof(struct rte_eth_conf));
 
-	/*set configuration of DCB in vt mode and DCB in non-vt mode*/
-	retval = get_eth_dcb_conf(pid, &port_conf, dcb_mode, num_tcs, pfc_en);
-	if (retval < 0)
-		return retval;
+	/* set configuration of DCB in vt mode and DCB in non-vt mode */
+	get_eth_dcb_conf(&port_conf, dcb_mode, num_tcs, pfc_en);
+
 	port_conf.rxmode.offloads |= RTE_ETH_RX_OFFLOAD_VLAN_FILTER;
 	/* remove RSS HASH offload for DCB in vt mode */
 	if (port_conf.rxmode.mq_mode == RTE_ETH_MQ_RX_VMDQ_DCB) {
-- 
2.20.1