On Wed, Sep 2, 2015 at 8:38 PM, Tom Herbert <t...@herbertland.com> wrote: > On Wed, Sep 2, 2015 at 9:46 AM, Rustad, Mark D <mark.d.rus...@intel.com> > wrote:
>> Note: NETIF_F_HW_CSUM is a superset of NETIF_F_IP_CSUM + NETIF_F_IPV6_CSUM. >> It means that device can fill TCP/UDP-like checksum anywhere in the packets >> whatever headers there might be. >> The device can't do whatever, wherever. There is always a limit to the >> offset to the inner headers that can be handled, for instance. > If the device does NETIF_F_HW_CSUM then inner/outer headers are > irrelevant at least in the non-GSO case. All the device needs to do is > compute the checksum from start and write the answer at the given > offset. No protocol awareness needed in the device, no need to parse > headers on transmit. Tom, could you elaborate a little further on the semantics/requirements for devices supporting NETIF_F_HW_CSUM, specifically, AFAIU this isn't a TX equivalent of supporting checksum complete on RX, right? when you say "write the answer at the given offset" what non-common answers are you expecting devices to produce? how the kernel is hinting to the device on the nature on the expected answer beyond the offset? Or. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
