Re: [dpdk-dev] [PATCH] ixgbe: fix a problem with NIC TSO offload

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of miroslaw.walukiewicz@intel.com
> Sent: Tuesday, December 09, 2014 5:15 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH] ixgbe: fix a problem with NIC TSO offload
> 
> From: Miroslaw Walukiewicz <miroslaw.walukiewicz@intel.com>
> 
> The patch fixes a minor issue with setting up of TSO feature for
> ixgbe NICs.
> 
> The values for l4_len and tso_segsz was chagned first by txoffload mask
> and next set up in the NIC descriptor.
> 
> Signed-off-by: Mirek Walukiewicz <miroslaw.walukiewicz@intel.com>
> ---
>  lib/librte_pmd_ixgbe/ixgbe_rxtx.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> index 8559ef6..c9c3104 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> @@ -390,13 +390,13 @@ ixgbe_set_xmit_ctx(struct igb_tx_queue* txq,
>  		type_tucmd_mlhl = IXGBE_ADVTXD_TUCMD_IPV4 |
>  			IXGBE_ADVTXD_TUCMD_L4T_TCP |
>  			IXGBE_ADVTXD_DTYP_CTXT | IXGBE_ADVTXD_DCMD_DEXT;
> +		mss_l4len_idx |= tx_offload.tso_segsz << IXGBE_ADVTXD_MSS_SHIFT;
> +		mss_l4len_idx |= tx_offload.l4_len << IXGBE_ADVTXD_L4LEN_SHIFT;

Didn't  understand your comment above...
By whom tx_offload.l4_len will be changed?
As I can see, below only tx_offload_mask is updated, tx_offload is intact.
Konstantin

> 
>  		tx_offload_mask.l2_len = ~0;
>  		tx_offload_mask.l3_len = ~0;
>  		tx_offload_mask.l4_len = ~0;
>  		tx_offload_mask.tso_segsz = ~0;
> -		mss_l4len_idx |= tx_offload.tso_segsz << IXGBE_ADVTXD_MSS_SHIFT;
> -		mss_l4len_idx |= tx_offload.l4_len << IXGBE_ADVTXD_L4LEN_SHIFT;
>  	} else { /* no TSO, check if hardware checksum is needed */
>  		if (ol_flags & PKT_TX_IP_CKSUM) {
>  			type_tucmd_mlhl = IXGBE_ADVTXD_TUCMD_IPV4;