[dpdk-dev] doc: update ixgbe doc

  Add more explanation about how to disable MDD on
kernel PF.

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
---
 doc/guides/nics/ixgbe.rst | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
  

> -----Original Message-----
> From: Lu, Wenzhuo
> Sent: Wednesday, May 3, 2017 6:55 AM
> To: dev@dpdk.org
> Cc: Mcnamara, John <john.mcnamara@intel.com>; Lu, Wenzhuo
> <wenzhuo.lu@intel.com>
> Subject: [PATCH] doc: update ixgbe doc
> 
> Add more explanation about how to disable MDD on kernel PF.
> 
> Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
> ---
>  doc/guides/nics/ixgbe.rst | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/doc/guides/nics/ixgbe.rst b/doc/guides/nics/ixgbe.rst index
> 130765b..6773fe5 100644
> --- a/doc/guides/nics/ixgbe.rst
> +++ b/doc/guides/nics/ixgbe.rst
> @@ -186,9 +186,12 @@ the advanced context descriptor should be set and set
> it. And DPDK has to ask  the info about the header length from the upper
> layer, because parsing the  packet itself is not acceptable. So, it's too
> expensive to support MDD.
>  When using kernel PF + DPDK VF on x550, please make sure using the kernel
> -driver that disables MDD or can disable MDD. (Some kernel driver can use
> -this CLI 'insmod ixgbe.ko MDD=0,0' to disable MDD. Some kernel driver
> disables -it by default.)
> +PF driver that disables MDD or can disable MDD.
> +Some kernel driver already disables MDD by default.
> +Some kernel driver can use this CLI "insmod ixgbe.ko MDD=0,0" to disable
> MDD.
> +Every "0" in the CLI means a port. Users need to add more "0"s if the
> +machine has more ports. For example, if there're 6 ixgbe ports, the CLI
> +should be changed to "insmod ixgbe.ko MDD=0,0,0,0,0,0".

Something like this would be better:

...
When using kernel PF + DPDK VF on x550, please make sure to use a kernel
PF driver that disables MDD or can disable MDD.

Some kernel drivers already disable MDD by default while some kernels can use
the command ``insmod ixgbe.ko MDD=0,0`` to disable MDD. Each "0" in the
command refers to a port. For example, if there are 6 ixgbe ports, the command
should be changed to ``insmod ixgbe.ko MDD=0,0,0,0,0,0``.
  

Hi John,

> -----Original Message-----
> From: Mcnamara, John
> Sent: Wednesday, May 10, 2017 12:39 AM
> To: Lu, Wenzhuo; dev@dpdk.org
> Subject: RE: [PATCH] doc: update ixgbe doc
> 
> 
> 
> > -----Original Message-----
> > From: Lu, Wenzhuo
> > Sent: Wednesday, May 3, 2017 6:55 AM
> > To: dev@dpdk.org
> > Cc: Mcnamara, John <john.mcnamara@intel.com>; Lu, Wenzhuo
> > <wenzhuo.lu@intel.com>
> > Subject: [PATCH] doc: update ixgbe doc
> >
> > Add more explanation about how to disable MDD on kernel PF.
> >
> > Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
> > ---
> >  doc/guides/nics/ixgbe.rst | 9 ++++++---
> >  1 file changed, 6 insertions(+), 3 deletions(-)
> >
> > diff --git a/doc/guides/nics/ixgbe.rst b/doc/guides/nics/ixgbe.rst
> > index
> > 130765b..6773fe5 100644
> > --- a/doc/guides/nics/ixgbe.rst
> > +++ b/doc/guides/nics/ixgbe.rst
> > @@ -186,9 +186,12 @@ the advanced context descriptor should be set
> and
> > set it. And DPDK has to ask  the info about the header length from the
> > upper layer, because parsing the  packet itself is not acceptable. So,
> > it's too expensive to support MDD.
> >  When using kernel PF + DPDK VF on x550, please make sure using the
> > kernel -driver that disables MDD or can disable MDD. (Some kernel
> > driver can use -this CLI 'insmod ixgbe.ko MDD=0,0' to disable MDD.
> > Some kernel driver disables -it by default.)
> > +PF driver that disables MDD or can disable MDD.
> > +Some kernel driver already disables MDD by default.
> > +Some kernel driver can use this CLI "insmod ixgbe.ko MDD=0,0" to
> > +disable
> > MDD.
> > +Every "0" in the CLI means a port. Users need to add more "0"s if the
> > +machine has more ports. For example, if there're 6 ixgbe ports, the
> > +CLI should be changed to "insmod ixgbe.ko MDD=0,0,0,0,0,0".
> 
> Something like this would be better:
> 
> ...
> When using kernel PF + DPDK VF on x550, please make sure to use a kernel
> PF driver that disables MDD or can disable MDD.
> 
> Some kernel drivers already disable MDD by default while some kernels can
> use the command ``insmod ixgbe.ko MDD=0,0`` to disable MDD. Each "0" in
> the command refers to a port. For example, if there are 6 ixgbe ports, the
> command should be changed to ``insmod ixgbe.ko MDD=0,0,0,0,0,0``.
Thanks for your comments. I'll reword the patch.