From 1d973d8f4c149523a15c1c0813f204bb89d4e588 Mon Sep 17 00:00:00 2001 From: Igor Chauskin Date: Tue, 26 Jan 2021 19:32:26 +0100 Subject: [PATCH] net/ena: prevent double doorbell Add per-tx-ring flag for packets that were pushed to HW but await doorbell. That is to prevent a situation when a doorbell is sent due to reaching Tx burst threshold and next send fails (e.g., due to queue full). In such case we shouldn't send another doorbell because there are no actual packets waiting for transmission. Fixes: c7519ea5eb8d ("net/ena: call additional doorbells if needed") Cc: stable@dpdk.org Signed-off-by: Igor Chauskin Reviewed-by: Michal Krawczyk --- drivers/net/ena/ena_ethdev.c | 7 +++++-- drivers/net/ena/ena_ethdev.h | 4 ++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c index 8a937d7f27..7acbf5e305 100644 --- a/drivers/net/ena/ena_ethdev.c +++ b/drivers/net/ena/ena_ethdev.c @@ -1282,6 +1282,7 @@ static int ena_tx_queue_setup(struct rte_eth_dev *dev, txq->ring_size = nb_desc; txq->size_mask = nb_desc - 1; txq->numa_socket_id = socket_id; + txq->pkts_without_db = false; txq->tx_buffer_info = rte_zmalloc("txq->tx_buffer_info", sizeof(struct ena_tx_buffer) * @@ -2522,6 +2523,7 @@ static int ena_xmit_mbuf(struct ena_ring *tx_ring, struct rte_mbuf *mbuf) tx_ring->id); ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq); tx_ring->tx_stats.doorbells++; + tx_ring->pkts_without_db = false; } /* prepare the packet's descriptors to dma engine */ @@ -2603,7 +2605,7 @@ static uint16_t eth_ena_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, for (sent_idx = 0; sent_idx < nb_pkts; sent_idx++) { if (ena_xmit_mbuf(tx_ring, tx_pkts[sent_idx])) break; - + tx_ring->pkts_without_db = true; rte_prefetch0(tx_pkts[ENA_IDX_ADD_MASKED(sent_idx, 4, tx_ring->size_mask)]); } @@ -2612,10 +2614,11 @@ static uint16_t eth_ena_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, ena_com_free_q_entries(tx_ring->ena_com_io_sq); /* If there are ready packets to be xmitted... */ - if (sent_idx > 0) { + if (likely(tx_ring->pkts_without_db)) { /* ...let HW do its best :-) */ ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq); tx_ring->tx_stats.doorbells++; + tx_ring->pkts_without_db = false; } ena_tx_cleanup(tx_ring); diff --git a/drivers/net/ena/ena_ethdev.h b/drivers/net/ena/ena_ethdev.h index 7bb74a1d06..ae235897ee 100644 --- a/drivers/net/ena/ena_ethdev.h +++ b/drivers/net/ena/ena_ethdev.h @@ -100,6 +100,10 @@ struct ena_ring { enum ena_ring_type type; enum ena_admin_placement_policy_type tx_mem_queue_type; + + /* Indicate there are Tx packets pushed to the device and wait for db */ + bool pkts_without_db; + /* Holds the empty requests for TX/RX OOO completions */ union { uint16_t *empty_tx_reqs; -- 2.20.1