On Wed, 2007-05-30 at 07:36 +1000, Herbert Xu wrote: > > I just checked e1000 and it's correct as it does use the csum_offset > when doing TX offload. However, you're definitely right that bnx2 > seems to be broken. > > > A few devices take a offset, starting point, and insertion point. This > > looks like > > the correct model. But no upper layer protocols other than IPV4/IPV6 can do > > checksum > > offload at present, so it seems moot. > > I could easily whip up a patch to get GRE to use it for a start :) > > > IMHO the correct solution would be to get rid if NETIF_F_HW_SUM and make a > > new flag > > NETIF_F_IPV6_SUM. Devices that can checksum both could do > > NETIF_F_IPV4_SUM|NETI_F_IPV6_SUM. > > We should definitely keep NETIF_F_HW_SUM for sane hardware such as the > e1000. Unfortunately we may just have to invent IPV6_SUM for the broken > ones. > > Ccing Michael to see if the bnx2 chip can actually do offset-based > checksum offload. >
bnx2 and tg3 cannot do offset-based checksumming because the hardware doesn't have room in the buffer descriptors to specify the offsets. So regrettably, the NETIF_F_HW_SUM flag has been misused in these drivers. A new NETIF_F_IPV6_SUM flag will be very useful for us. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
