Re: [dpdk-stable] [PATCH 18.11 18/19] net/bnxt: fix deferred start of Tx queues

[Kevin Traynor <ktraynor@redhat.com>]

On 18/12/2019 06:24, Somnath Kotur wrote:
> From: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> 
> [ upstream commit aa2c00702bad7b2c742e11a86cb9dbbb8364fd88 ]

> [ upstream commit 3955e26870bcc3336c87d1fabe6ebdf18b2a337b ]
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I believe this should be 2171e66f938fb86623ad7c16f5dbad3b33938142

and 3955e2687 is patch 19/19 in this series. I will make the change when
applying.

> 
> Driver should not change "deferred_start" state of the tx queues.
> It should get the state in queue_setup_op() and use that value.
> 
> Since the deferred start state was being used in the packet transmit
> functions to determine whether the queue has been stopped already,
> introduced a per-txq flag to track queue stopped/started state.
> 
> Fixes: 9b63c6fd70e3 ("net/bnxt: support Rx/Tx queue start/stop")
> 
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
> Reviewed-by: Lance Richardson <lance.richardson@broadcom.com>
> ---
>  drivers/net/bnxt/bnxt_txq.c | 6 ++++++
>  drivers/net/bnxt/bnxt_txq.h | 1 +
>  drivers/net/bnxt/bnxt_txr.c | 6 +++---
>  3 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/bnxt/bnxt_txq.c b/drivers/net/bnxt/bnxt_txq.c
> index b76ad05..cf6ddfb 100644
> --- a/drivers/net/bnxt/bnxt_txq.c
> +++ b/drivers/net/bnxt/bnxt_txq.c
> @@ -113,6 +113,7 @@ int bnxt_tx_queue_setup_op(struct rte_eth_dev *eth_dev,
>  	txq->bp = bp;
>  	txq->nb_tx_desc = nb_desc;
>  	txq->tx_free_thresh = tx_conf->tx_free_thresh;
> +	txq->tx_deferred_start = tx_conf->tx_deferred_start;
>  
>  	rc = bnxt_init_tx_ring_struct(txq, socket_id);
>  	if (rc)
> @@ -139,6 +140,11 @@ int bnxt_tx_queue_setup_op(struct rte_eth_dev *eth_dev,
>  
>  	eth_dev->data->tx_queues[queue_idx] = txq;
>  
> +	if (txq->tx_deferred_start)
> +		txq->tx_started = false;
> +	else
> +		txq->tx_started = true;
> +
>  out:
>  	return rc;
>  }
> diff --git a/drivers/net/bnxt/bnxt_txq.h b/drivers/net/bnxt/bnxt_txq.h
> index 720ca90..29b90bf 100644
> --- a/drivers/net/bnxt/bnxt_txq.h
> +++ b/drivers/net/bnxt/bnxt_txq.h
> @@ -24,6 +24,7 @@ struct bnxt_tx_queue {
>  	uint8_t			wthresh; /* Write-back threshold reg */
>  	uint32_t		ctx_curr; /* Hardware context states */
>  	uint8_t			tx_deferred_start; /* not in global dev start */
> +	uint8_t			tx_started; /* TX queue is started */
>  
>  	struct bnxt		*bp;
>  	int			index;
> diff --git a/drivers/net/bnxt/bnxt_txr.c b/drivers/net/bnxt/bnxt_txr.c
> index 95272c9..348b111 100644
> --- a/drivers/net/bnxt/bnxt_txr.c
> +++ b/drivers/net/bnxt/bnxt_txr.c
> @@ -418,7 +418,7 @@ uint16_t bnxt_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>  	bnxt_handle_tx_cp(txq);
>  
>  	/* Tx queue was stopped; wait for it to be restarted */
> -	if (txq->tx_deferred_start) {
> +	if (unlikely(!txq->tx_started)) {
>  		PMD_DRV_LOG(DEBUG, "Tx q stopped;return\n");
>  		return 0;
>  	}
> @@ -448,7 +448,7 @@ int bnxt_tx_queue_start(struct rte_eth_dev *dev, uint16_t tx_queue_id)
>  	struct bnxt_tx_queue *txq = bp->tx_queues[tx_queue_id];
>  
>  	dev->data->tx_queue_state[tx_queue_id] = RTE_ETH_QUEUE_STATE_STARTED;
> -	txq->tx_deferred_start = false;
> +	txq->tx_started = true;
>  	PMD_DRV_LOG(DEBUG, "Tx queue started\n");
>  
>  	return 0;
> @@ -463,7 +463,7 @@ int bnxt_tx_queue_stop(struct rte_eth_dev *dev, uint16_t tx_queue_id)
>  	bnxt_handle_tx_cp(txq);
>  
>  	dev->data->tx_queue_state[tx_queue_id] = RTE_ETH_QUEUE_STATE_STOPPED;
> -	txq->tx_deferred_start = true;
> +	txq->tx_started = false;
>  	PMD_DRV_LOG(DEBUG, "Tx queue stopped\n");
>  
>  	return 0;
>