Re: [dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting limitation

["Zhao1, Wei" <wei.zhao1@intel.com>]

HI, 

Why not add some more code 
"
	if (rx_conf->offloads & DEV_RX_OFFLOAD_SCATTER)
		dev->data->scattered_rx = 1;
" 

Into ixgbevf_dev_rx_init() to enable scatter mode when start device?


Reviewed-by: Wei Zhao <wei.zhao1@intel.com>


> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of David Harton
> Sent: Wednesday, April 3, 2019 9:19 AM
> To: dev@dpdk.org
> Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; David Harton <dharton@cisco.com>
> Subject: [dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting limitation
> 
> Currently, if requested MTU is bigger than mbuf size and scattered receive is
> not enabled, setting MTU to that value fails.
> 
> This patch allows setting this special MTU when device is stopped, because
> scattered_rx will be re-configured during next port start and driver may
> enable scattered receive according new MTU value.
> 
> After this patch, driver may select different receive function automatically
> after MTU set, according MTU values selected.
> 
> Signed-off-by: David Harton <dharton@cisco.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> b/drivers/net/ixgbe/ixgbe_ethdev.c
> index feec85634..0b962c8db 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -6346,20 +6346,22 @@ ixgbevf_dev_set_mtu(struct rte_eth_dev *dev,
> uint16_t mtu)  {
>  	struct ixgbe_hw *hw;
>  	uint32_t max_frame = mtu + IXGBE_ETH_OVERHEAD;
> -	struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
> +	struct rte_eth_dev_data *dev_data = dev->data;
> 
>  	hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> 
>  	if ((mtu < ETHER_MIN_MTU) || (max_frame >
> ETHER_MAX_JUMBO_FRAME_LEN))
>  		return -EINVAL;
> 
> -	/* refuse mtu that requires the support of scattered packets when
> this
> -	 * feature has not been enabled before.
> +	/* If device is started, refuse mtu that requires the support of
> +	 * scattered packets when this feature has not been enabled before.
>  	 */
> -	if (!(rx_conf->offloads & DEV_RX_OFFLOAD_SCATTER) &&
> +	if (dev_data->dev_started && !dev_data->scattered_rx &&
>  	    (max_frame + 2 * IXGBE_VLAN_TAG_SIZE >
> -	     dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM))
> +	     dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM)) {
> +		PMD_INIT_LOG(ERR, "Stop port first.");
>  		return -EINVAL;
> +	}
> 
>  	/*
>  	 * When supported by the underlying PF driver, use the
> IXGBE_VF_SET_MTU
> --
> 2.19.1