Hi, Nikita dev_conf.rxmode.max_rx_pkt_len is different with MTU concept. The max_rx_pkt_len indicates the maximum packet length it can receive, it should be larger than MTU.
There is another patch which is enabling set_mtu ops. http://dpdk.org/dev/patchwork/patch/12218/ You can definitely help to review and comment it. Thanks Jingjing > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Nikita Kozlov > Sent: Friday, May 06, 2016 11:51 PM > To: Zhang, Helin > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v1] net: i40e: add VLAN tag size to RXMAX > > Hello, > > On 09/ 1/15 07:34 AM, Zhang, Helin wrote: > >> -----Original Message----- > >> From: Vlad Zolotarov [mailto:vladz at cloudius-systems.com] > >> Sent: Monday, August 31, 2015 2:42 PM > >> To: dev at dpdk.org > >> Cc: Zhang, Helin; Ananyev, Konstantin; avi at cloudius-systems.com; Vlad > >> Zolotarov > >> Subject: [dpdk-dev] [PATCH v1] net: i40e: add VLAN tag size to RXMAX > >> > >> HW requires it regardless the presence of the VLAN tag in the received > frame. > >> Otherwise Rx frames are being filtered out on the MTU-4 boundary. > > Maximum packet length could have different meanings from MTU. I agree > > with you to have it be regardless of vlan tag length. > > > >> Signed-off-by: Vlad Zolotarov <vladz at cloudius-systems.com> > >> --- > >> drivers/net/i40e/i40e_rxtx.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/net/i40e/i40e_rxtx.c > >> b/drivers/net/i40e/i40e_rxtx.c index > >> eae4ab0..22aaeb1 100644 > >> --- a/drivers/net/i40e/i40e_rxtx.c > >> +++ b/drivers/net/i40e/i40e_rxtx.c > >> @@ -3156,7 +3156,7 @@ i40e_rx_queue_init(struct i40e_rx_queue *rxq) > >> rx_ctx.hsplit_0 = I40E_HEADER_SPLIT_ALL; > >> else > >> rx_ctx.hsplit_0 = I40E_HEADER_SPLIT_NONE; > >> - rx_ctx.rxmax = rxq->max_pkt_len; > >> + rx_ctx.rxmax = rxq->max_pkt_len + I40E_VLAN_TAG_SIZE; > > It needs to take into account the double vlan case, and also VF case. > > It seems it needs more code changes. Thank you for the contribution! > I was wondering if this "bug" haven't been forgotten ? Even if it his not > patched yet maybe it is worth an entry in the documentation ? > > > > Regards, > > Helin > > > >> rx_ctx.tphrdesc_ena = 1; > >> rx_ctx.tphwdesc_ena = 1; > >> rx_ctx.tphdata_ena = 1; > >> -- > >> 2.1.0