Re: [PATCH] bnx2x: fix rx checksum validation for IPv6

["Eilon Greenstein" <eilong@broadcom.com>]

On Fri, 2012-09-14 at 01:14 +0200, Eric Dumazet wrote:
> On Fri, 2012-09-14 at 00:59 +0200, Michal Schmidt wrote:
> > Commit d6cb3e41 "bnx2x: fix checksum validation" caused a performance
> > regression for IPv6. Rx checksum offload does not work. IPv6 packets
> > are passed to the stack with CHECKSUM_NONE.
> > 
> > The hardware obviously cannot perform IP checksum validation for IPv6,
> > because there is no checksum in the IPv6 header. This should not prevent
> > us from setting CHECKSUM_UNNECESSARY.
> > 
> > Tested on BCM57711.
> > 
> > Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
> > ---
> >  drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 12 +++++++-----
> >  1 file changed, 7 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
> > index af20c6e..e8e97a7 100644
> > --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
> > +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
> > @@ -662,14 +662,16 @@ void bnx2x_csum_validate(struct sk_buff *skb, union eth_rx_cqe *cqe,
> >  				 struct bnx2x_fastpath *fp,
> >  				 struct bnx2x_eth_q_stats *qstats)
> >  {
> > -	/* Do nothing if no IP/L4 csum validation was done */
> > -
> > +	/* Do nothing if no L4 csum validation was done.
> > +	 * We do not check whether IP csum was validated. For IPv4 we assume
> > +	 * that if the card got as far as validating the L4 csum, it also
> > +	 * validated the IP csum. IPv6 has no IP csum.
> > +	 */
> >  	if (cqe->fast_path_cqe.status_flags &
> > -	    (ETH_FAST_PATH_RX_CQE_IP_XSUM_NO_VALIDATION_FLG |
> > -	     ETH_FAST_PATH_RX_CQE_L4_XSUM_NO_VALIDATION_FLG))
> > +	    ETH_FAST_PATH_RX_CQE_L4_XSUM_NO_VALIDATION_FLG)
> >  		return;
> >  
> > -	/* If both IP/L4 validation were done, check if an error was found. */
> > +	/* If L4 validation was done, check if an error was found. */
> >  
> >  	if (cqe->fast_path_cqe.type_error_flags &
> >  	    (ETH_FAST_PATH_RX_CQE_IP_BAD_XSUM_FLG |
> 
> Thanks for fixing this bug !
> 
> Acked-by: Eric Dumazet <edumazet@google.com>

Indeed - thanks Michal!

Acked-by: Eilon Greenstein <eilong@broadcom.com>