Re: [PATCH] net/mlx5: add supported hash function check

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

On Mon, Apr 02, 2018 at 12:41:33PM +0000, Xueming(Steven) Li wrote:
> > this device should to the same instead of refusing it
> 
> Just double confirm, is it "do the same"? are you suggesting not denying
> unsupported hash function in rte_eth_dev_configure()?

I mean, if others PMD are ignoring non supported values, but only using
what they support, this PMD should do the same.

> From quick view of ixgbe code, kind of try best, would like to hear from 
> other PMDs on how this interpreted.

Don't expect other maintainers to answer you if you don't ask them
directly.

> > -----Original Message-----
> > From: Nélio Laranjeiro [mailto:nelio.laranjeiro@6wind.com]
> > Sent: Monday, March 26, 2018 7:40 PM
> > To: Xueming(Steven) Li <xuemingl@mellanox.com>
> > Cc: Adrien Mazarguil <adrien.mazarguil@6wind.com>; Shahaf Shuler
> > <shahafs@mellanox.com>; dev@dpdk.org
> > Subject: Re: [PATCH] net/mlx5: add supported hash function check
> > 
> > On Thu, Mar 22, 2018 at 10:42:44AM +0000, Xueming(Steven) Li wrote:
> > > Just remind, denying unsupported hash function in
> > > rte_eth_dev_configure() might impact some user app using PMD that simply
> > ignoring them silently.
> > 
> > If the default behavior from other devices is to use only possible values,
> > this device should to the same instead of refusing it.
> > 
> > > Testpmd command "port config <port> rss all" should be updated as well
> > > to 'all' supported values from rte_eth_dev_info, I'll include this
> > > change in next version.
> > >
> > > > -----Original Message-----
> > > > From: Nélio Laranjeiro [mailto:nelio.laranjeiro@6wind.com]
> > > > Sent: Monday, March 19, 2018 4:30 PM
> > > > To: Xueming(Steven) Li <xuemingl@mellanox.com>
> > > > Cc: Adrien Mazarguil <adrien.mazarguil@6wind.com>; Shahaf Shuler
> > > > <shahafs@mellanox.com>; dev@dpdk.org
> > > > Subject: Re: [PATCH] net/mlx5: add supported hash function check
> > > >
> > > > On Sun, Mar 18, 2018 at 03:37:20PM +0800, Xueming Li wrote:
> > > > > Add supported RSS hash function check in device configuration to
> > > > > have better error verbosity for application developers.
> > > > >
> > > > > Signed-off-by: Xueming Li <xuemingl@mellanox.com>
> > > > > ---
> > > > >  drivers/net/mlx5/mlx5_ethdev.c | 8 ++++++++
> > > > >  1 file changed, 8 insertions(+)
> > > > >
> > > > > diff --git a/drivers/net/mlx5/mlx5_ethdev.c
> > > > > b/drivers/net/mlx5/mlx5_ethdev.c index b73cb53..175a1ff 100644
> > > > > --- a/drivers/net/mlx5/mlx5_ethdev.c
> > > > > +++ b/drivers/net/mlx5/mlx5_ethdev.c
> > > > > @@ -346,6 +346,14 @@ struct ethtool_link_settings {
> > > > >  		      rx_offloads, supp_rx_offloads);
> > > > >  		return ENOTSUP;
> > > > >  	}
> > > > > +	if (dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf &
> > > > > +	    MLX5_RSS_HF_MASK) {
> > > > > +		ERROR("Some RSS hash function not supported "
> > > > > +		      "requested 0x%" PRIx64 " supported 0x%" PRIx64,
> > > > > +		      dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf,
> > > > > +		      (uint64_t)(~MLX5_RSS_HF_MASK));
> > > > > +		return ENOTSUP;
> > > > > +	}
> > > > >  	if (use_app_rss_key &&
> > > > >  	    (dev->data->dev_conf.rx_adv_conf.rss_conf.rss_key_len !=
> > > > >  	     rss_hash_default_key_len)) {
> > > > > --
> > > > > 1.8.3.1
> > > > >
> > > >
> > > > I would answer than an application should not try to configure
> > > > something not advertise by the device.
> > > > This information is present in struct rte_eth_dev_info returned by
> > > > mlx5_dev_infos_get() and thus the devops of the device.
> > > >
> > > > Seems rte_eth_dev_configure() should be fixed to avoid configuring
> > > > wrong values.
> > > >
> > > > Regards,
> > > >
> > > > --
> > > > Nélio Laranjeiro
> > > > 6WIND
> > 
> > --
> > Nélio Laranjeiro
> > 6WIND

-- 
Nélio Laranjeiro
6WIND