1 From e89ea2a038987102d9eb0a7ea217d7a301b484cb Mon Sep 17 00:00:00 2001
2 From: John Daley <johndale@cisco.com>
3 Date: Thu, 24 Mar 2016 14:00:39 -0700
4 Subject: [PATCH 21/22] enic: fix TX hang when number of packets > queue
7 If the nb_pkts parameter to rte_eth_tx_burst() was greater than
8 the TX descriptor count, a completion was not being requested
9 from the NIC, so descriptors would not be released back to the
10 host causing a lock-up.
12 Introduce a limit of how many TX descriptors can be used in a single
13 call to the enic PMD burst TX function before requesting a completion.
15 Fixes: d739ba4c6abf ("enic: improve Tx packet rate")
17 Signed-off-by: John Daley <johndale@cisco.com>
19 drivers/net/enic/enic_ethdev.c | 20 ++++++++++++++++----
20 drivers/net/enic/enic_res.h | 1 +
21 2 files changed, 17 insertions(+), 4 deletions(-)
23 diff --git a/drivers/net/enic/enic_ethdev.c b/drivers/net/enic/enic_ethdev.c
24 index 6c3c734..61bb83c 100644
25 --- a/drivers/net/enic/enic_ethdev.c
26 +++ b/drivers/net/enic/enic_ethdev.c
27 @@ -510,7 +510,7 @@ static void enicpmd_remove_mac_addr(struct rte_eth_dev *eth_dev, __rte_unused ui
28 static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
36 @@ -522,6 +522,7 @@ static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
37 unsigned short vlan_id;
38 unsigned short ol_flags;
39 uint8_t last_seg, eop;
40 + unsigned int host_tx_descs = 0;
42 for (index = 0; index < nb_pkts; index++) {
44 @@ -537,6 +538,7 @@ static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
49 pkt_len = tx_pkt->pkt_len;
50 vlan_id = tx_pkt->vlan_tci;
51 ol_flags = tx_pkt->ol_flags;
52 @@ -546,9 +548,19 @@ static uint16_t enicpmd_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
53 next_tx_pkt = tx_pkt->next;
54 seg_len = tx_pkt->data_len;
56 - eop = (pkt_len == inc_len) || (!next_tx_pkt);
58 - (index == ((unsigned int)nb_pkts - 1));
63 + if ((pkt_len == inc_len) || !next_tx_pkt) {
65 + /* post if last packet in batch or > thresh */
66 + if ((index == (nb_pkts - 1)) ||
67 + (host_tx_descs > ENIC_TX_POST_THRESH)) {
72 enic_send_pkt(enic, wq, tx_pkt, (unsigned short)seg_len,
73 !frags, eop, last_seg, ol_flags, vlan_id);
75 diff --git a/drivers/net/enic/enic_res.h b/drivers/net/enic/enic_res.h
76 index 33f2e84..00fa71d 100644
77 --- a/drivers/net/enic/enic_res.h
78 +++ b/drivers/net/enic/enic_res.h
81 #define ENIC_NON_TSO_MAX_DESC 16
82 #define ENIC_DEFAULT_RX_FREE_THRESH 32
83 +#define ENIC_TX_POST_THRESH (ENIC_MIN_WQ_DESCS / 2)
85 #define ENIC_SETTING(enic, f) ((enic->config.flags & VENETF_##f) ? 1 : 0)