From: Baruch Siach <baruch@tkos.co.il>
Date: Wed, 25 Aug 2021 10:05:44 +0000 (+0300)
Subject: net/af_xdp: fix zero-copy Tx queue drain
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=0f2ffb49ce29351fad043377a6d2f144f3c52afb;p=dpdk.git

net/af_xdp: fix zero-copy Tx queue drain

Call xsk_ring_prod__submit() before kick_tx() so that the kernel
consumer sees the updated state of Tx ring. Otherwise, Tx packets are
stuck in the ring until the next call to af_xdp_tx_zc().

Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
Cc: stable@dpdk.org

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Ciara Loftus <ciara.loftus@intel.com>
---

diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 74ffa45112..9bea0a895a 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -527,7 +527,6 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 
 			if (!xsk_ring_prod__reserve(&txq->tx, 1, &idx_tx)) {
 				rte_pktmbuf_free(local_mbuf);
-				kick_tx(txq, cq);
 				goto out;
 			}
 
@@ -551,10 +550,9 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		tx_bytes += mbuf->pkt_len;
 	}
 
-	kick_tx(txq, cq);
-
 out:
 	xsk_ring_prod__submit(&txq->tx, count);
+	kick_tx(txq, cq);
 
 	txq->stats.tx_pkts += count;
 	txq->stats.tx_bytes += tx_bytes;