[PATCH v2] net/nfp: update how MAX MTU is read

[Ferruh Yigit]

On 4/20/2022 2:46 PM, Walter Heymans wrote:
> The 'max_rx_pktlen' value was previously read from hardware, which was
> set by the running firmware. This caused confusion due to different
> meanings of 'MAX_MTU'. This patch updates the 'max_rx_pktlen' to the
> maximum value that the NFP NIC can support. The 'max_mtu' value that is
> read from hardware, is assigned to the 'dev_info->max_mtu' variable.
> 
> If more layer 2 metadata must be used, the firmware can be updated to
> report a smaller 'max_mtu' value.
> 
> The constant defined for NFP_FRAME_SIZE_MAX is derived for the maximum
> supported buffer size of 10240, minus 136 bytes that is reserved by the
> hardware and another 56 bytes reserved for expansion in firmware. This
> results in a usable maximum packet length of 10048 bytes.
> 
> Signed-off-by: Walter Heymans <walter.heymans at corigine.com>
> Signed-off-by: Niklas Söderlund <niklas.soderlund at corigine.com>
> Reviewed-by: Louis Peens <louis.peens at corigine.com>
> Reviewed-by: Chaoyong He <chaoyong.he at corigine.com>
> Reviewed-by: Richard Donkin <richard.donkin at corigine.com>

Applied to dpdk-next-net/main, thanks.