From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 3/3] net: Fix drivers advertising HW_CSUM feature to use csum_start Date: Wed, 15 Dec 2010 10:25:36 -0800 Message-ID: <20101215102536.6430274b@nehalam> References: <20101214190727.0ed1a925@nehalam> <20101215181655.GA29962@rere.qmqm.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: quoted-printable Cc: Roopa Prabhu , Dumazet , Jiri Pirko , e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, Vasanthy, Jie Yang , Eric, Kolluri , "VMware, Inc." , Brice Goglin , H, Andrew Gallatin , Joe Perches , David Wang , Shreyas Bhatewara , "David S. Miller" , Sweeten To: =?iso-8859-2?B?TWljaGGzIE1pcm9zs2F3?= Return-path: In-Reply-To: <20101215181655.GA29962@rere.qmqm.pl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Wed, 15 Dec 2010 19:16:55 +0100 Micha=B3 Miros=B3aw wrote: > On Tue, Dec 14, 2010 at 07:07:27PM -0800, Stephen Hemminger wrote: > > On Wed, 15 Dec 2010 02:24:08 +0100 (CET) > > Micha=B3 Miros=B3aw wrote: > > > Some drivers are using skb_transport_offset(skb) instead of skb->csum= _start > > > for NETIF_F_HW_CSUM offload. This does not matter now, but if someone > > > implements checksumming of encapsulated packets then this will break = silently. > > > = > > > TSO output paths are left as they are, since they are for IP+TCP only > > > (might be worth converting though). > > > = > > > Signed-off-by: Micha=B3 Miros=B3aw > > Which if any of these drivers did you test on real hardware? > = > I'm running it on skge, with additional patch that changes it to use > NETIF_F_HW_CSUM instead of NETIF_F_IP_CSUM. BTW, why it is not advertising > full HW checksum in vanilla kernel? Are there any known hardware bugs in = there? > = > Best Regards, > Micha=B3 Miros=B3aw The driver was written from vendor sk98lin driver and that driver only did IP checksum, therefore I did not trust the hardware. The chipset is old, and not used in new designs, no documentation is up to date (and I didn't have any). Please don't enable non-IPv4 checksum offload on this hardware, there is too big a risk of it not working on all hardware. -- = ---------------------------------------------------------------------------= --- Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.co= m/community/wired