Re: [dpdk-dev] [PATCH v3 10/17] net/ionic: add basic port operations

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 12/9/2019 9:46 PM, Alfredo Cardigliano wrote:
> Add support for port start/stop and handle basic features
> including mtu and link up/down.
> 
> Signed-off-by: Alfredo Cardigliano <cardigliano@ntop.org>
> Reviewed-by: Shannon Nelson <snelson@pensando.io>

<...>

> +static int
> +ionic_dev_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu)
> +{
> +	struct ionic_lif *lif = IONIC_ETH_DEV_TO_LIF(eth_dev);
> +	int err;
> +
> +	IONIC_PRINT_CALL();
> +
> +	/*
> +	 * Max frame size is MTU + Ethernet header + VLAN + QinQ
> +	 * (plus ETHER_CRC_LEN if the adapter is able to keep CRC)
> +	 * uint32_t frame_size = mtu + RTE_ETHER_HDR_LEN + 4 + 4;
> +	 */

'max_rx_pkt_len' is a user provided configuration value, you may need to check
if provide MTU value is bigger than it and fail if scattered Rx is not supported.


> +
> +	/* Check that mtu is within the allowed range */
> +	if (mtu < IONIC_MIN_MTU || mtu > IONIC_MAX_MTU)
> +		return -EINVAL;

This check is now redundant and can be removed, since 'dev_info->min_mtu' &
'dev_info->max_mtu' are provided.