net/bnxt: fix Tx descriptor status implementation

With Tx completion batching, a single transmit completion
can correspond to one or more transmit descriptors, adjust
implementation to account for this.

RTE_ETH_TX_DESC_DONE should be returned for descriptors that
are available for use instead of RTE_ETH_TX_DESC_UNAVAIL.

Fixes: 5735eb241947 ("net/bnxt: support Tx batching")
Fixes: 478ed3bb7b9d ("net/bnxt: support Tx descriptor status")
Cc: stable@dpdk.org
Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index 74ade93..4d51a20 100644 (file)
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -3296,41 +3296,49 @@ static int
 bnxt_tx_descriptor_status_op(void *tx_queue, uint16_t offset)
 {
        struct bnxt_tx_queue *txq = (struct bnxt_tx_queue *)tx_queue;
-       struct bnxt_tx_ring_info *txr;
-       struct bnxt_cp_ring_info *cpr;
-       struct rte_mbuf **tx_buf;
-       struct tx_pkt_cmpl *txcmp;
-       uint32_t cons, cp_cons;
+       struct bnxt_cp_ring_info *cpr = txq->cp_ring;
+       uint32_t ring_mask, raw_cons, nb_tx_pkts = 0;
+       struct bnxt_ring *cp_ring_struct;
+       struct cmpl_base *cp_desc_ring;
        int rc;
 
-       if (!txq)
-               return -EINVAL;
-
        rc = is_bnxt_in_error(txq->bp);
        if (rc)
                return rc;
 
-       cpr = txq->cp_ring;
-       txr = txq->tx_ring;
-
        if (offset >= txq->nb_tx_desc)
                return -EINVAL;
 
-       cons = RING_CMP(cpr->cp_ring_struct, offset);
-       txcmp = (struct tx_pkt_cmpl *)&cpr->cp_desc_ring[cons];
-       cp_cons = cpr->cp_raw_cons;
+       /* Return "desc done" if descriptor is available for use. */
+       if (bnxt_tx_bds_in_hw(txq) <= offset)
+               return RTE_ETH_TX_DESC_DONE;
 
-       if (cons > cp_cons) {
-               if (CMPL_VALID(txcmp, cpr->valid))
-                       return RTE_ETH_TX_DESC_UNAVAIL;
-       } else {
-               if (CMPL_VALID(txcmp, !cpr->valid))
-                       return RTE_ETH_TX_DESC_UNAVAIL;
+       raw_cons = cpr->cp_raw_cons;
+       cp_desc_ring = cpr->cp_desc_ring;
+       cp_ring_struct = cpr->cp_ring_struct;
+       ring_mask = cpr->cp_ring_struct->ring_mask;
+
+       /* Check to see if hw has posted a completion for the descriptor. */
+       while (1) {
+               struct tx_cmpl *txcmp;
+               uint32_t cons;
+
+               cons = RING_CMPL(ring_mask, raw_cons);
+               txcmp = (struct tx_cmpl *)&cp_desc_ring[cons];
+
+               if (!CMP_VALID(txcmp, raw_cons, cp_ring_struct))
+                       break;
+
+               if (CMP_TYPE(txcmp) == TX_CMPL_TYPE_TX_L2)
+                       nb_tx_pkts += rte_le_to_cpu_32(txcmp->opaque);
+
+               if (nb_tx_pkts > offset)
+                       return RTE_ETH_TX_DESC_DONE;
+
+               raw_cons = NEXT_RAW_CMP(raw_cons);
        }
-       tx_buf = &txr->tx_buf_ring[cons];
-       if (*tx_buf == NULL)
-               return RTE_ETH_TX_DESC_DONE;
 
+       /* Descriptor is pending transmit, not yet completed by hardware. */
        return RTE_ETH_TX_DESC_FULL;
 }