Re: [dpdk-dev] [PATCH] ethdev: forbid MTU set before device configure

["Jiang, YuX" <yux.jiang@intel.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Andrew Rybchenko
> Sent: Friday, October 22, 2021 6:18 PM
> To: Thomas Monjalon <thomas@monjalon.net>; Yigit, Ferruh
> <ferruh.yigit@intel.com>; Ajit Khaparde <ajit.khaparde@broadcom.com>;
> Huisong Li <lihuisong@huawei.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Xu, Rosen <rosen.xu@intel.com>
> Cc: dev@dpdk.org; Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> Subject: [dpdk-dev] [PATCH] ethdev: forbid MTU set before device
> configure
> 
> From: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> 
> rte_eth_dev_configure() always sets MTU to either dev_conf.rxmode.mtu
> or RTE_ETHER_MTU if application doesn't provide the value.
> So, there is no point to allow rte_eth_dev_set_mtu() before since set value
> will be overwritten on configure anyway.
> 
> Fixes: 1bb4a528c41f ("ethdev: fix max Rx packet length")
> 
> Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> ---
>  lib/ethdev/rte_ethdev.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c index
> 4ea5a657e0..0d7dd68dc1 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -3728,6 +3728,13 @@ rte_eth_dev_set_mtu(uint16_t port_id, uint16_t
> mtu)
>  			return ret;
>  	}
> 
> +	if (dev->data->dev_configured == 0) {
> +		RTE_ETHDEV_LOG(ERR,
> +			"Port %u must be configured before MTU set\n",
> +			port_id);
> +		return -EINVAL;
> +	}
> +
>  	ret = (*dev->dev_ops->mtu_set)(dev, mtu);
>  	if (ret == 0)
>  		dev->data->mtu = mtu;
> --
> 2.30.2
Hi Ivan,

We meet an issue based on this patch when test dpdk21.11-rc1.
BugID: https://bugs.dpdk.org/show_bug.cgi?id=864, could you pls have a look?