Re: [dpdk-dev] [PATCH v2 05/22] net/e1000: fix the jumbo frame flag condition for mtu set

["Guo, Jia" <jia.guo@intel.com>]

Acked-by: Jeff Guo <jia.guo@intel.com>

> -----Original Message-----
> From: Steve Yang <stevex.yang@intel.com>
> Sent: Thursday, December 17, 2020 5:23 PM
> To: dev@dpdk.org
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> Subject: [PATCH v2 05/22] net/e1000: fix the jumbo frame flag condition for
> mtu set
> 
> The jumbo frame uses the 'RTE_ETHER_MAX_LEN' as boundary condition,
> but the Ether overhead is larger than 18 when it supports VLAN tag. That will
> cause the jumbo flag rx offload is wrong when MTU size is 'RTE_ETHER_MTU'.
> 
> This fix will change the boundary condition with 'RTE_ETHER_MTU' and
> overhead.
> 
> Fixes: ef990fb56e55 ("net/e1000: convert to new Rx offloads API")
> 
> Signed-off-by: Steve Yang <stevex.yang@intel.com>
> ---
>  drivers/net/e1000/e1000_ethdev.h | 2 +-
>  drivers/net/e1000/em_ethdev.c    | 5 ++---
>  drivers/net/e1000/igb_ethdev.c   | 2 +-
>  3 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/e1000/e1000_ethdev.h
> b/drivers/net/e1000/e1000_ethdev.h
> index 4755a5f333..3b4d9c3ee6 100644
> --- a/drivers/net/e1000/e1000_ethdev.h
> +++ b/drivers/net/e1000/e1000_ethdev.h
> @@ -97,7 +97,7 @@
>   */
>  #define E1000_ETH_OVERHEAD (RTE_ETHER_HDR_LEN +
> RTE_ETHER_CRC_LEN + \
>  				VLAN_TAG_SIZE)
> -
> +#define E1000_ETH_MAX_LEN (RTE_ETHER_MTU + E1000_ETH_OVERHEAD)
>  /*
>   * Maximum number of Ring Descriptors.
>   *
> diff --git a/drivers/net/e1000/em_ethdev.c
> b/drivers/net/e1000/em_ethdev.c index 8ee9422bf4..2036c6e917 100644
> --- a/drivers/net/e1000/em_ethdev.c
> +++ b/drivers/net/e1000/em_ethdev.c
> @@ -1799,8 +1799,7 @@ eth_em_mtu_set(struct rte_eth_dev *dev,
> uint16_t mtu)
>  	if (ret != 0)
>  		return ret;
> 
> -	frame_size = mtu + RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN +
> -		VLAN_TAG_SIZE;
> +	frame_size = mtu + E1000_ETH_OVERHEAD;
> 
>  	/* check that mtu is within the allowed range */
>  	if (mtu < RTE_ETHER_MIN_MTU || frame_size >
> dev_info.max_rx_pktlen) @@ -1816,7 +1815,7 @@ eth_em_mtu_set(struct
> rte_eth_dev *dev, uint16_t mtu)
>  	rctl = E1000_READ_REG(hw, E1000_RCTL);
> 
>  	/* switch to jumbo mode if needed */
> -	if (frame_size > RTE_ETHER_MAX_LEN) {
> +	if (frame_size > E1000_ETH_MAX_LEN) {
>  		dev->data->dev_conf.rxmode.offloads |=
>  			DEV_RX_OFFLOAD_JUMBO_FRAME;
>  		rctl |= E1000_RCTL_LPE;
> diff --git a/drivers/net/e1000/igb_ethdev.c
> b/drivers/net/e1000/igb_ethdev.c index 647aa8d995..dfe87508c2 100644
> --- a/drivers/net/e1000/igb_ethdev.c
> +++ b/drivers/net/e1000/igb_ethdev.c
> @@ -4369,7 +4369,7 @@ eth_igb_mtu_set(struct rte_eth_dev *dev,
> uint16_t mtu)
>  	rctl = E1000_READ_REG(hw, E1000_RCTL);
> 
>  	/* switch to jumbo mode if needed */
> -	if (frame_size > RTE_ETHER_MAX_LEN) {
> +	if (frame_size > E1000_ETH_MAX_LEN) {
>  		dev->data->dev_conf.rxmode.offloads |=
>  			DEV_RX_OFFLOAD_JUMBO_FRAME;
>  		rctl |= E1000_RCTL_LPE;
> --
> 2.17.1