Re: possible issue between bridge igmp/multicast handling & bnx2x on kernel 2.6.34 and >

[Eric Dumazet <eric.dumazet@gmail.com>]

Le vendredi 07 janvier 2011 à 11:40 +0100, Yann Dupont a écrit :
> Le 04/01/2011 14:40, Yann Dupont a écrit :
> ...
> > We just added BCM57711 10G cards (bnx2x driver) on our blade servers 
> > (connected to 10G Power Connect M8024).
> > Since then, we are experiencing random lost of packets.
> >
> > Symptom : packets are lost on some vlans for a few seconds, then 
> > things go back to normal (and stops again a few minutes later)
> >
> 
> As I didn't had answer so far , I digged a little more and captured more 
> packets.
> I just noticed that an event trigger that problem : IPv6 neighbor 
> discovery packet .
> 
> This is , of course, a multicast packet.
> 
> Just saw that 2.6.36.3 should include this fix :
> 
> > From: David Stevens<dlstevens@us.ibm.com>
> >
> > [ Upstream commit 04bdf0c9a451863e50fff627713a900a2cabb998 ]
> >
> > This patch fixes a missing ntohs() for bridge IPv6 multicast snooping.
> But in fact , I just tested, and this doesn't cure the problem :(
> 
> This bug
> - only occurs with bnx2x with tagged vlans, attached to bridges. Other 
> interfaces (bnx2 , for exemple) works fine. bnx2x without bridges works 
> fine.
> - only happens when bridge is compiled with CONFIG_BRIDGE_IGMP_SNOOPING 
> (default setting)
> - is triggered by IPv6 neighbor discovery packet. Just after that 
> packet, others packets are discarded for some time.
> - packets originating from same vlans are not affected, only packets 
> previously routed are discarded. Examinating those packets, I don't 
> undersand why, apart TTL (and mac address), they seems similar .
> - has origin circa 2.6.33 :
> fe2d7c70b747d5d968f4e8fa210676d49d40059 is the first bad commit
> commit 3fe2d7c70b747d5d968f4e8fa210676d49d40059
> Author: Herbert Xu <herbert@gondor.apana.org.au>
> Date:   Sun Feb 28 00:49:38 2010 -0800
> 
>      bridge: Add multicast start/stop hooks
> 
>      This patch hooks up the bridge start/stop and add/delete/disable
>      port functions to the new multicast module.
> 
>      Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>      Signed-off-by: David S. Miller <davem@davemloft.net>
> 
> 
> 
> What can I do to help fixing this bug ?
> regards,
> 

Please take a look at whole thread at
https://lkml.org/lkml/2010/8/13/200

I guess this is a similar problem.