Re: [dpdk-dev] [PATCH v3] i40e: fix TSO issue for tx function

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Mar 31, 2016 at 08:15:58PM +0800, Zhe Tao wrote:
> Issue:
> 
> when using the following CLI in testpmd to enable ipv6 TSO feature
> (set --txqflags=0 in the testpmd command)
> 	set verbose 1
> 	csum set ip hw 0
> 	csum set udp hw 0
> 	csum set tcp hw 0
> 	csum set sctp hw 0
> 	csum set outer-ip hw 0
> 	csum parse_tunnel on 0
> 	tso set 800 0
> 	set fwd csum
> 	start
> 
> We will not get what we want, the ipv6 packets sent out from IXIA can be 
> received by i40e, but cannot forward to another port.
> The root cause is when HW doing the TSO offload for packets, it does not only
> depends on the context descriptor to define the MSS and TSO payload size, it
> also need to know whether this packets is ipv4 or ipv6, we use 
> i40e_txd_enable_checksum to generate the related fields for data descriptor.
> But PMD will not call i40e_txd_enable_checksum if only the TSO offload flag is
> set. The reason why ipv4 works fine for TSO in testpmd csum mode is csum engine
> will set the ip csum flag when the packet is ipv4 and TSO is enabled but 
> will not set the flag for ipv6 and this flag will cause the
> i40e_txd_enable_checksum to be invoked. For both the cases the TSO flag will be
> set, so we need to use TSO flag to trigger the i40e_txd_enable_checksum.
> The right logic here is we enable csum offload for both ipv4 and ipv6 when TSO
> flag is set.
>  
> Fixes: e3f0151f (i40e: enable Tx checksum only for offloaded packets)

Missing sign-off in this version.

> ---
>  drivers/net/i40e/i40e_rxtx.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
> index 81cde6c..6e3fd25 100644
> --- a/drivers/net/i40e/i40e_rxtx.c
> +++ b/drivers/net/i40e/i40e_rxtx.c
> @@ -76,6 +76,7 @@
>  #define I40E_TX_CKSUM_OFFLOAD_MASK (		 \
>  		PKT_TX_IP_CKSUM |		 \
>  		PKT_TX_L4_MASK |		 \
> +		PKT_TX_TCP_SEG |		 \
>  		PKT_TX_OUTER_IP_CKSUM)
>  
>  static uint16_t i40e_xmit_pkts_simple(void *tx_queue,
> -- 
> v2: changed condition check for ipv6 TSO checksum offload
>     use a more clear check method which include both ipv4 & ipv6 TSO
> v3: edited the commit log and title because this problem exists for both
>     ipv4 and ipv6
> 2.1.4
> 

This version history is clearer when placed immediately below the commit description.
You also need to use a 3-character cut-line, rather than 2-char, in that case.

/Bruce