[dpdk-dev] [PATCH] net/i40e: fix max frame size checking

[Zhang, Qi Z]

> -----Original Message-----
> From: Ananyev, Konstantin
> Sent: Thursday, July 26, 2018 5:17 PM
> To: Wu, Yanglong <yanglong.wu at intel.com>; dev at dpdk.org
> Cc: Zhang, Qi Z <qi.z.zhang at intel.com>; Bie, Tiwei <tiwei.bie at intel.com>; Yao,
> Lei A <lei.a.yao at intel.com>; Wu, Yanglong <yanglong.wu at intel.com>
> Subject: RE: [dpdk-dev] [PATCH] net/i40e: fix max frame size checking
> 
> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Yanglong Wu
> > Sent: Thursday, July 26, 2018 7:46 AM
> > To: dev at dpdk.org
> > Cc: Zhang, Qi Z <qi.z.zhang at intel.com>; Bie, Tiwei
> > <tiwei.bie at intel.com>; Yao, Lei A <lei.a.yao at intel.com>; Wu, Yanglong
> > <yanglong.wu at intel.com>
> > Subject: [dpdk-dev] [PATCH] net/i40e: fix max frame size checking
> >
> > No need to check max frame size in TX, the checking should be done in
> > up layer protocal. This checking will lead to fail for TSO or other
> > application cases.
> 
> Not sure why is that?
> i40e doesn't support single packet bigger then 9.5KB (or so), as I remember.
> For TSO the limit is 256KB - yes, it is bibber, but still there is a limit.

I think we can't support more than 8 segment for TSO, right? so if the limit is 256KB, seems it is a redundant.

> Might be we need to change that check, but I think we still need to keep it.
> Konstantin

> 
> >
> > Fixes: bfeed0262b0c ("net/i40e: check illegal packets")
> >
> > Signed-off-by: Yanglong Wu <yanglong.wu at intel.com>
> > ---
> >  drivers/net/i40e/i40e_rxtx.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/i40e/i40e_rxtx.c
> > b/drivers/net/i40e/i40e_rxtx.c index 3be87fe6a..baad433a7 100644
> > --- a/drivers/net/i40e/i40e_rxtx.c
> > +++ b/drivers/net/i40e/i40e_rxtx.c
> > @@ -1459,8 +1459,7 @@ i40e_prep_pkts(__rte_unused void *tx_queue,
> struct rte_mbuf **tx_pkts,
> >  		}
> >
> >  		/* check the size of packet */
> > -		if (m->pkt_len > I40E_FRAME_SIZE_MAX ||
> > -		    m->pkt_len < I40E_TX_MIN_PKT_LEN) {
> > +		if (m->pkt_len < I40E_TX_MIN_PKT_LEN) {
> >  			rte_errno = -EINVAL;
> >  			return i;
> >  		}
> > --
> > 2.11.0