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

["Chautru, Nicolas" <nicolas.chautru@intel.com>]

> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Monday, October 11, 2021 1:29 PM
> To: Chautru, Nicolas <nicolas.chautru@intel.com>
> Cc: dev@dpdk.org; gakhil@marvell.com; hemant.agrawal@nxp.com; Zhang,
> Mingshan <mingshan.zhang@intel.com>; Joshi, Arun
> <arun.joshi@intel.com>; Tom Rix <trix@redhat.com>
> Subject: Re: [dpdk-dev] [PATCH v3 5/6] doc: clarification of usage of HARQ in
> bbdev doc
> 
> 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.

Thanks Thomas. 

>