Re: [dpdk-dev] [PATCH] ethdev: fix device info getting

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 12.07.2018 08:27, Wenzhuo Lu wrote:
> The device information cannot be gotten correctly before
> the configuration is set. Because on some NICs the
> information has dependence on the configuration.
>
> Fixes: 3be82f5cc5e3 ("ethdev: support PMD-tuned Tx/Rx parameters")
> Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
> ---
>   lib/librte_ethdev/rte_ethdev.c | 47 +++++++++++++++++++++---------------------
>   1 file changed, 24 insertions(+), 23 deletions(-)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 3d556a8..9d60bea 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -1017,28 +1017,6 @@ struct rte_eth_dev *
>   
>   	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
>   
> -	dev = &rte_eth_devices[port_id];
> -
> -	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_infos_get, -ENOTSUP);
> -	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_configure, -ENOTSUP);
> -
> -	rte_eth_dev_info_get(port_id, &dev_info);
> -
> -	/* If number of queues specified by application for both Rx and Tx is
> -	 * zero, use driver preferred values. This cannot be done individually
> -	 * as it is valid for either Tx or Rx (but not both) to be zero.
> -	 * If driver does not provide any preferred valued, fall back on
> -	 * EAL defaults.
> -	 */
> -	if (nb_rx_q == 0 && nb_tx_q == 0) {
> -		nb_rx_q = dev_info.default_rxportconf.nb_queues;
> -		if (nb_rx_q == 0)
> -			nb_rx_q = RTE_ETH_DEV_FALLBACK_RX_NBQUEUES;
> -		nb_tx_q = dev_info.default_txportconf.nb_queues;
> -		if (nb_tx_q == 0)
> -			nb_tx_q = RTE_ETH_DEV_FALLBACK_TX_NBQUEUES;
> -	}
> -
>   	if (nb_rx_q > RTE_MAX_QUEUES_PER_PORT) {
>   		RTE_ETHDEV_LOG(ERR,
>   			"Number of RX queues requested (%u) is greater than max supported(%d)\n",
> @@ -1053,6 +1031,11 @@ struct rte_eth_dev *
>   		return -EINVAL;
>   	}
>   
> +	dev = &rte_eth_devices[port_id];
> +
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_infos_get, -ENOTSUP);
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_configure, -ENOTSUP);
> +
>   	if (dev->data->dev_started) {
>   		RTE_ETHDEV_LOG(ERR,
>   			"Port %u must be stopped to allow configuration\n",
> @@ -1060,8 +1043,26 @@ struct rte_eth_dev *
>   		return -EBUSY;
>   	}
>   
> -	/* Copy the dev_conf parameter into the dev structure */
> +	/* Copy the dev_conf parameter into the dev structure,
> +	 * then get the info.
> +	 */
>   	memcpy(&dev->data->dev_conf, &local_conf, sizeof(dev->data->dev_conf));
> +	rte_eth_dev_info_get(port_id, &dev_info);
> +
> +	/* If number of queues specified by application for both Rx and Tx is
> +	 * zero, use driver preferred values. This cannot be done individually
> +	 * as it is valid for either Tx or Rx (but not both) to be zero.
> +	 * If driver does not provide any preferred valued, fall back on
> +	 * EAL defaults.
> +	 */
> +	if (nb_rx_q == 0 && nb_tx_q == 0) {
> +		nb_rx_q = dev_info.default_rxportconf.nb_queues;
> +		if (nb_rx_q == 0)
> +			nb_rx_q = RTE_ETH_DEV_FALLBACK_RX_NBQUEUES;
> +		nb_tx_q = dev_info.default_txportconf.nb_queues;
> +		if (nb_tx_q == 0)
> +			nb_tx_q = RTE_ETH_DEV_FALLBACK_TX_NBQUEUES;

Values assigned in this branch are not checked against
RTE_MAX_QUEUES_PER_PORT and RTE_MAX_QUEUES_PER_PORT now

> +	}
>   
>   	/*
>   	 * Check that the numbers of RX and TX queues are not greater