Re: [dpdk-dev] [PATCH] ethdev: fix setting of MAC address

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 12/14/2017 08:15 PM, Olivier Matz wrote:
> From: Laurent Hardy <laurent.hardy@6wind.com>
>
> When a new mac address is set, it is saved in dev->data->mac_addrs
> before the ethdev handler is called.
>
> First, it is inconsistent with the other ethdev functions
> rte_eth_dev_mac_addr_remove() and rte_eth_dev_mac_addr_add().
>
> Moreover, it prevents the drivers from wrongly comparing the old address
> and the new one, like it's done in i40evf driver:
>
> 	if (is_same_ether_addr(mac_addr, dev->data->mac_addrs))
> 		return;
>
> Fixes: 943c2d899a0c ("net/i40e: set VF MAC from VF")
> Fixes: 854d8ad4ef68 ("ethdev: add default mac address modifier")
> Cc: stable@dpdk.org
>
> Signed-off-by: Laurent Hardy <laurent.hardy@6wind.com>
> ---
>   lib/librte_ether/rte_ethdev.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index 4f492e3db..297c02a54 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -2643,11 +2643,11 @@ rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct ether_addr *addr)
>   	dev = &rte_eth_devices[port_id];
>   	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->mac_addr_set, -ENOTSUP);
>   
> +	(*dev->dev_ops->mac_addr_set)(dev, addr);
> +
>   	/* Update default address in NIC data structure */
>   	ether_addr_copy(addr, &dev->data->mac_addrs[0]);
>   
> -	(*dev->dev_ops->mac_addr_set)(dev, addr);
> -
>   	return 0;
>   }

NACK, unfortunately it will break net/sfc in one of branches when a new MAC
is set using restart. It relies on the fact that a new MAC is already 
available in
device data.