[dpdk-dev] [PATCH v12 0/6] add Tx preparation

Harish Patil harish.patil at qlogic.com
Wed Nov 30 17:34:26 CET 2016

>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
>    * 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.
>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"

qede PMD doesn’t currently support TSO yet, it only supports Tx TCP/UDP/IP
csum offloads.
So Tx preparation isn’t applicable. So as of now -
"it is OK, we do not need any checksum preparation for TSO"


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