[dpdk-dev] [PATCH v12 0/6] add Tx preparation
ajit.khaparde at broadcom.com
Wed Nov 30 20:37:40 CET 2016
Nov 28, 2016 at 5:03 AM, Thomas Monjalon <thomas.monjalon at 6wind.com> 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
> 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
> 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'
> Please, we need a comment for each driver saying
> "it is OK, we do not need any checksum preparation for TSO"
> "yes we have to implement tx_prepare or TSO will not work in this mode"
The bnxt devices
don't need pse
udo header checksum in the packet for TSO or TX
"it is OK, we do not need any checksum preparation for TSO"
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