Re: [dpdk-dev] [PATCH v3 5/6] doc: clarification of usage of HARQ in bbdev doc

[Thomas Monjalon <thomas@monjalon.net>]

12/09/2021 14:44, Tom Rix:
> On 9/7/21 6:15 PM, Nicolas Chautru wrote:
> > New paragraph detailing typical VRAN usecase and mapping
> > to bbdev API usage.
> >
> > Signed-off-by: Nicolas Chautru <nicolas.chautru@intel.com>
> > ---
> >   doc/guides/prog_guide/bbdev.rst | 23 +++++++++++++++++++++++
> >   1 file changed, 23 insertions(+)
> >
> > diff --git a/doc/guides/prog_guide/bbdev.rst b/doc/guides/prog_guide/bbdev.rst
> > index 8bd7cba..f39b62f 100644
> > --- a/doc/guides/prog_guide/bbdev.rst
> > +++ b/doc/guides/prog_guide/bbdev.rst
> > @@ -1054,6 +1054,29 @@ capability RTE_BBDEV_LDPC_INTERNAL_HARQ_MEMORY_OUT_ENABLE is set
> >   then the HARQ is stored in memory internal to the device and not visible
> >   to BBDEV.
> >   
> > +.. note::

blank line missing

> > +    More explicitly for a typical usage of HARQ retransmission in a VRAN
> > +    application using a HW PMD, there will be 2 cases.
> > +
> > +    For 1st transmission, only the HARQ output is enabled :

no space before ":"

> > +
> > +    - the harq_combined_output.offset is provided to a given address. ie. typically an integer index * 32K, where the index is tracked by the application based on code block index for a given UE and HARQ process.
> > +
> > +    - the related operation flag would notably include RTE_BBDEV_LDPC_HQ_COMBINE_OUT_ENABLE and RTE_BBDEV_LDPC_HARQ_6BIT_COMPRESSION.
> > +
> > +    - note that not explicit flush or reset of the memory is required.

"*no* explicit"

> > +
> > +    For 2nd transmission, an input is also required to benefit from HARQ combination gain:
> > +
> > +    - the changes mentioned above are the same (note that rvIndex may be adjusted).
> > +
> > +    - the operation flag would additionally include the LDPC_HQ_COMBINE_IN_ENABLE flag.
> > +
> > +    - the harq_combined_input.offset must set to the address of the related code block (ie. same as the harq_combine_output index above for the same code block, HARQ process, UE).

"must *be* set"

> > +
> > +    - the harq_combined_input.length must be set to the length which was provided back in the related harq_combined_output.length when it has processed and dequeued (previous HARQ iteration).

lines are too long

> > +
> > +
> 
> Fine.
> 
> Reviewed-by: Tom Rix <trix@redhat.com>

No, it isn't fine.
Fixing some typos and formatting while pulling in main.