Hi Thomas, On Monday, November 11/28/16, 2016 at 16:33:06 +0530, Thomas Monjalon wrote: > We need attention of every PMD developers on this thread. > > Reminder of what Konstantin suggested: > " > - if the PMD supports TX offloads AND > - if to be able use any of these offloads the upper layer SW would have to: > * modify the contents of the packet OR > * obey HW specific restrictions > then it is a PMD developer responsibility to provide tx_prep() that would > implement > expected modifications of the packet contents and restriction checks. > Otherwise, tx_prep() implementation is not required and can be safely set to > NULL. > " > > I copy/paste also my previous conclusion: > > Before txprep, there is only one API: the application must prepare the > packets checksum itself (get_psd_sum in testpmd). > With txprep, the application have 2 choices: keep doing the job itself > or call txprep which calls a PMD-specific function. > The question is: does non-Intel drivers need a checksum preparation for TSO? > Will it behave well if txprep does nothing in these drivers? > > When looking at the code, most of drivers handle the TSO flags. > But it is hard to know whether they rely on the pseudo checksum or not. > > git grep -l 'PKT_TX_UDP_CKSUM\|PKT_TX_TCP_CKSUM\|PKT_TX_TCP_SEG' drivers/net/ > > drivers/net/bnxt/bnxt_txr.c > drivers/net/cxgbe/sge.c > drivers/net/e1000/em_rxtx.c > drivers/net/e1000/igb_rxtx.c > drivers/net/ena/ena_ethdev.c > drivers/net/enic/enic_rxtx.c > drivers/net/fm10k/fm10k_rxtx.c > drivers/net/i40e/i40e_rxtx.c > drivers/net/ixgbe/ixgbe_rxtx.c > drivers/net/mlx4/mlx4.c > drivers/net/mlx5/mlx5_rxtx.c > drivers/net/nfp/nfp_net.c > drivers/net/qede/qede_rxtx.c > drivers/net/thunderx/nicvf_rxtx.c > drivers/net/virtio/virtio_rxtx.c > drivers/net/vmxnet3/vmxnet3_rxtx.c > > Please, we need a comment for each driver saying > "it is OK, we do not need any checksum preparation for TSO" > or > "yes we have to implement tx_prepare or TSO will not work in this mode"
For CXGBE PMD, "it is OK, we do not need any checksum preparation for TSO". Thanks, Rahul
