Re: [dpdk-dev] [PATCH] examples/ip_reassembly: enable scatter mode for Mellanox PMDs

[Slava Ovsiienko <viacheslavo@mellanox.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Stephen Hemminger
> Sent: Tuesday, November 19, 2019 3:15
> To: Thinh Tran <thinhtr@linux.vnet.ibm.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] examples/ip_reassembly: enable scatter
> mode for Mellanox PMDs
> 
> On Mon, 18 Nov 2019 12:18:33 -0600
> Thinh Tran <thinhtr@linux.vnet.ibm.com> wrote:
> 
> > Simple change to enable scatter for Mellanox CX4/CX5 PMDs to run this
> > example
> >
> > Signed-off-by: Thinh Tran <thinhtr@linux.vnet.ibm.com>
> > ---
> >  examples/ip_reassembly/main.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/examples/ip_reassembly/main.c
> > b/examples/ip_reassembly/main.c index d59e6d02f..f881b89d1 100644
> > --- a/examples/ip_reassembly/main.c
> > +++ b/examples/ip_reassembly/main.c
> > @@ -1109,6 +1109,9 @@ main(int argc, char **argv)
> >  				port_conf.rx_adv_conf.rss_conf.rss_hf,
> >  				local_port_conf.rx_adv_conf.rss_conf.rss_hf);
> >  		}
> > +		/* Mellanox PMDs needs scatter mode to be explicitly
> enabled */
> > +		if (!strcmp(dev_info.driver_name, "net_mlx5"))
> > +			local_port_conf.rxmode.offloads |=
> DEV_RX_OFFLOAD_SCATTER;
> 
> This is a bad, bad precedent.
> Either fix MLX driver or enable it for all PMD's.
> Forcing applications to do workarounds indicates a poor design abstraction.
+1
What about checking whether PMD supports scattering offload and enable these one?