Re: [PATCH net-next v2] af-packet: new flag to indicate all csums are good

[Jakub Kicinski]

On Tue, 2 Jun 2020 21:22:11 +0200 Victor Julien wrote:
> - receiver uses nfp (netronome) driver: TP_STATUS_CSUM_VALID set for
> every packet, including the bad TCP ones
> - receiver uses ixgbe driver: TP_STATUS_CSUM_VALID not set for the bad
> packets.
> 
> Again purely based on 'git grep' it seems nfp does not support
> UNNECESSARY, while ixgbe does.
> 
> (my original testing was with the nfp only, so now I at least understand
> my original thinking)

FWIW nfp defaults to CHECKSUM_COMPLETE if the device supports it (see
if you have RXCSUM_COMPLETE in the probe logs). It supports UNNECESSARY
as well, but IDK if there is a way to choose  the preferred checksum
types in the stack :( You'd have to edit the driver and remove the
NFP_NET_CFG_CTRL_CSUM_COMPLETE from the NFP_NET_CFG_CTRL_RXCSUM_ANY
mask to switch to using UNNECESSARY.