Re: [dpdk-dev] [PATCH] net/mlx5: allow multi probing

[Yongseok Koh <yskoh@mellanox.com>]

On Wed, Oct 03, 2018 at 01:01:23AM -0700, Ophir Munk wrote:
> Implement probing of a device multiple times, see [1].
> Consecutive probing requests with a devargs string may contain
> repetitive master and representors devices for which eth device should
> be created. If an eth device already exists - silently ignore it.
> 
> [1]
> Serie: ("eal: allow hotplug to skip an already probed device")

A typo? Series?

For the title, either 'multi-probing' or 'multiple probing'.
And I suggest

	net/mlx5: allow multiple probing for representor

And I have only nitpickings below ;-)

> https://patches.dpdk.org/project/dpdk/list/?series=1580
> 
> Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
> index b2b0aaa..16a8b9d 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -736,6 +736,7 @@
>  	struct ether_addr mac;
>  	char name[RTE_ETH_NAME_MAX_LEN];
>  	int own_domain_id = 0;
> +	uint16_t port_id;
>  	unsigned int i;
>  
>  	/* Determine if this port representor is supposed to be spawned. */
> @@ -758,6 +759,17 @@
>  			return NULL;
>  		}
>  	}
> +	/* Build device name */

Better to put a period (.), if it is a sentence.

> +	if (!switch_info->representor)
> +		rte_strlcpy(name, dpdk_dev->name, sizeof(name));
> +	else
> +		snprintf(name, sizeof(name), "%s_representor_%u",
> +			 dpdk_dev->name, switch_info->port_name);
> +	/* if dev (master or representor) is already spawned - return NULL */

How about,
	/* Check if the device is already spawned. */

"return NULL" is so obvious from the code.

> +	if (rte_eth_dev_get_port_by_name(name, &port_id) == 0) {
> +		rte_errno = EBUSY;

Semantically, shouldn't it be EEXIST and add the condition in probe()?

> +		return NULL;
> +	}
>  	/* Prepare shared data between primary and secondary process. */
>  	mlx5_prepare_shared_data();
>  	errno = 0;
> @@ -864,11 +876,6 @@
>  		DEBUG("ibv_query_device_ex() failed");
>  		goto error;
>  	}
> -	if (!switch_info->representor)
> -		rte_strlcpy(name, dpdk_dev->name, sizeof(name));
> -	else
> -		snprintf(name, sizeof(name), "%s_representor_%u",
> -			 dpdk_dev->name, switch_info->port_name);
>  	DRV_LOG(DEBUG, "naming Ethernet device \"%s\"", name);
>  	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
>  		eth_dev = rte_eth_dev_attach_secondary(name);
> @@ -1298,9 +1305,6 @@ struct mlx5_dev_spawn_data {
>  	assert(pci_drv == &mlx5_driver);
>  	errno = 0;
>  
> -	if (rte_dev_is_probed(&pci_dev->device))
> -		return -EEXIST;
> -
>  	ibv_list = mlx5_glue->get_device_list(&ret);
>  	if (!ibv_list) {
>  		rte_errno = errno ? errno : ENOSYS;
> @@ -1412,7 +1416,7 @@ struct mlx5_dev_spawn_data {
>  		if (!list[i].eth_dev) {
>  			if (rte_errno != EBUSY)

I meant this to be,
			if (rte_errno != EBUSY && rte_errno != EEXIST)


Thanks,
Yongseok

>  				break;
> -			/* Device is disabled, ignore it. */
> +			/* Device is disabled or already spawned. Ignore it. */
>  			continue;
>  		}
>  		restore = list[i].eth_dev->data->dev_flags;
> -- 
> 1.8.3.1
>