RE: [PATCH v3] net/nfp: fix mtu settings

[Nole Zhang <peng.zhang@corigine.com>]

Thanks for your advice.

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@xilinx.com>
> Sent: 2022年4月21日 2:55
> To: Nole Zhang <peng.zhang@corigine.com>; dev@dpdk.org; Niklas
> Soderlund <niklas.soderlund@corigine.com>
> Cc: Heinrich Kuhn <heinrich.kuhn@corigine.com>; stable@dpdk.org;
> Chaoyong He <chaoyong.he@corigine.com>; Louis Peens
> <louis.peens@corigine.com>
> Subject: Re: [PATCH v3] net/nfp: fix mtu settings
> 
> On 3/30/2022 4:17 AM, Peng Zhang wrote:
> > 1.When the setting mtu is higher than flbufsz, the mtu doesn't work.
> > But it doesn't have any notice about this restrict.
> > 2.add the min_mtu and max_mtu in the nfp_net_infos_get() to avoid the
> > setting mtu isn't in the range
> >
> > This patch will add these restrict of nfp mtu.
> >
> 
> +Niklas, as he is the maintainer of the PMD.
> 
> Can you please prefer uppercase 'MTU' in title/commit log and error log?
> 

Yes,  I will use the MTU replace the mtu.

> I assume scattered_rx is not supported by the device, which enables
> receiving packets bigger than mbuf data size.
> 
> > Fixes: d4a27a3b092a ("nfp: add basic features")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Peng Zhang <peng.zhang@corigine.com>
> > Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
> > Signed-off-by: Louis Peens <louis.peens@corigine.com>
> > ---
> > v3:
> > * git summary
> >
> > v2:
> > * add the min_mtu and max_mtu in the nfp_net_infos_get()
> > ---
> >
> >   drivers/net/nfp/nfp_common.c | 9 +++++++++
> >   1 file changed, 9 insertions(+)
> >
> > diff --git a/drivers/net/nfp/nfp_common.c
> > b/drivers/net/nfp/nfp_common.c index f8978e803a..4e48e33a63 100644
> > --- a/drivers/net/nfp/nfp_common.c
> > +++ b/drivers/net/nfp/nfp_common.c
> > @@ -693,6 +693,8 @@ nfp_net_infos_get(struct rte_eth_dev *dev, struct
> > rte_eth_dev_info *dev_info)
> >
> >   	hw = NFP_NET_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >
> > +	dev_info->max_mtu = (uint16_t)hw->max_mtu;
> > +	dev_info->min_mtu = RTE_ETHER_MIN_MTU;
> >   	dev_info->max_rx_queues = (uint16_t)hw->max_rx_queues;
> >   	dev_info->max_tx_queues = (uint16_t)hw->max_tx_queues;
> >   	dev_info->min_rx_bufsize = RTE_ETHER_MIN_MTU; @@ -956,6
> +958,13 @@
> > nfp_net_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
> >   		return -EBUSY;
> >   	}
> >
> > +	/* the setting mtu is lower than flbufsz */
> > +	if (mtu > hw->flbufsz) {
> > +		PMD_DRV_LOG(ERR, "the setting mtu must be lower than
> current
> > +mbufsize of %d",
> 
> You may want to start log with uppercase as done in other logs, for
> consistency.
> Also may want to print the MTU value in the log.
> 

Yes,  I will use the MTU replace the mtu.

> > +			    hw->flbufsz);
> > +		return -ERANGE;
> > +	}
> 
> Should this be checked in 'nfb_eth_dev_configure()' too, where 'dev->data-
> >mtu' can be set?
> 

You mean in the nfp_net_configure(), we need through the rxmode->mtu to check the mtu?
I will consider it.

Thanks for your advice again.
> > +
> >   	/* writing to configuration space */
> >   	nn_cfg_writel(hw, NFP_NET_CFG_MTU, mtu);
> >