netdev - RE: Netxen packet loss with VLANs and LRO (was: [PATCH] netxen: fix LRO disable warning)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <99737F4847ED0A48AECC9F4A1974A4B80FD10E8E3C@MNEXMB2.qlogic.org>
Date:	Tue, 5 Apr 2011 00:38:11 -0500
From:	Amit Salecha <amit.salecha@...gic.com>
To:	Marc Haber <mh+netdev@...schlus.de>
CC:	"davem@...emloft.net" <davem@...emloft.net>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	Ameen Rahman <ameen.rahman@...gic.com>,
	Rajesh Borundia <rajesh.borundia@...gic.com>
Subject: RE: Netxen packet loss with VLANs and LRO (was: [PATCH] netxen:
  fix	LRO disable warning)

>
> Hi,
>
> On Mon, Mar 21, 2011 at 03:37:08AM -0700, Amit Kumar Salecha wrote:
> > netxen_nic_set_flags() rejects data if other flag than ETH_FLAG_LRO
> is set.
> > Driver also supports NETIF_F_HW_VLAN_TX.
> > Now compare data with ethtool_op_get_flags(), to get all supported
> features.
>
> Could that be the cause for packet loss on kernel 2.6.38.2 if:
>
>   - receiving card is NX3031 [4040:0100]
>   - frames are received with VLAN tags
>   - large received offload is on.
>

If ip_forwarding or routing is enable ....then you may see packet loss.

> Packet Loss of this kind is noticed when doing TCP data transfers
> towards the host with the Netxen Interface and the TCP session is
> terminated on the Netxen host itself. TCP sessions routed through the
> Netxen host are not affected.
>
> My ethtool doesn't allow me to influence the LRO setting alone - it is
> disabled when I set rx off but doesn't come on again when rx is set to
> on again. So, ethtool -K rx off, ethtool -K rx on fixes the issue.
>
If rx csum is disabled, LRO will be disable. LRO won't be enabled automatically if you enable rx csum.
You need to explicitly enable LRO.

> Is this a known bug, maybe with an available patch?
>
You need to retest with this patch http://patchwork.ozlabs.org/patch/88060/. This patch got applied instead of mine.


This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.