Re: [dpdk-dev] net/i40e: add promiscuous configure unsupported check

["Zhang, Xiao" <xiao.zhang@intel.com>]

Hi Ferruh,

> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Monday, March 2, 2020 5:09 PM
> To: Zhang, Xiao <xiao.zhang@intel.com>; dev@dpdk.org
> Cc: Xing, Beilei <beilei.xing@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>;
> stable@dpdk.org
> Subject: Re: [dpdk-dev] net/i40e: add promiscuous configure unsupported check
> 
> On 2/28/2020 3:22 AM, Xiao Zhang wrote:
> > Return ENOTSUP error code when configuring i40evf promiscuous mode to
> > fix port start hang issue on platforms which are unsupported to
> > configure promiscuous mode.
> 
> Hi Xiao,
> 
> What is the cause of the hang, was the application keep trying because of the "-
> EAGAIN" error?

When starting port, rte_eth_dev_start will call rte_eth_dev_config_restore in which promisc configure will be called to enable/disable promiscuous mode.
Since "-EAGAIN" was returned if platforms not supported to configure promisc mode, it would return error and stop port starting.

        /* replay promiscuous configuration */
        /*
         * use callbacks directly since we don't need port_id check and
         * would like to bypass the same value set
         */
        if (rte_eth_promiscuous_get(port_id) == 1 &&
            *dev->dev_ops->promiscuous_enable != NULL) {
                ret = eth_err(port_id,
                              (*dev->dev_ops->promiscuous_enable)(dev));
                if (ret != 0 && ret != -ENOTSUP) {
                        RTE_ETHDEV_LOG(ERR,
                                "Failed to enable promiscuous mode for device (port %u): %s\n",
                                port_id, rte_strerror(-ret));
                        return ret;
                }
        } else if (rte_eth_promiscuous_get(port_id) == 0 &&
                   *dev->dev_ops->promiscuous_disable != NULL) {
                ret = eth_err(port_id,
                              (*dev->dev_ops->promiscuous_disable)(dev));
                if (ret != 0 && ret != -ENOTSUP) {
                        RTE_ETHDEV_LOG(ERR,
                                "Failed to disable promiscuous mode for device (port %u): %s\n",
                                port_id, rte_strerror(-ret));
                        return ret;
                }
        }

> 
> >
> > Fixes: ddc7cb0d9453 ("net/i40e: re-program promiscuous mode on VF
> > interface")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Xiao Zhang <xiao.zhang@intel.com>
> > ---
> >  drivers/net/i40e/i40e_ethdev_vf.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/net/i40e/i40e_ethdev_vf.c
> > b/drivers/net/i40e/i40e_ethdev_vf.c
> > index c34f520..244397e 100644
> > --- a/drivers/net/i40e/i40e_ethdev_vf.c
> > +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> > @@ -2191,6 +2191,8 @@ i40evf_dev_promiscuous_enable(struct rte_eth_dev
> *dev)
> >  	ret = i40evf_config_promisc(dev, 1, vf->promisc_multicast_enabled);
> >  	if (ret == 0)
> >  		vf->promisc_unicast_enabled = TRUE;
> > +	else if (ret == I40E_NOT_SUPPORTED)
> > +		ret = -ENOTSUP;
> >  	else
> >  		ret = -EAGAIN;
> >
> > @@ -2206,6 +2208,8 @@ i40evf_dev_promiscuous_disable(struct
> rte_eth_dev *dev)
> >  	ret = i40evf_config_promisc(dev, 0, vf->promisc_multicast_enabled);
> >  	if (ret == 0)
> >  		vf->promisc_unicast_enabled = FALSE;
> > +	else if (ret == I40E_NOT_SUPPORTED)
> > +		ret = -ENOTSUP;
> >  	else
> >  		ret = -EAGAIN;
> >
> > @@ -2221,6 +2225,8 @@ i40evf_dev_allmulticast_enable(struct rte_eth_dev
> *dev)
> >  	ret = i40evf_config_promisc(dev, vf->promisc_unicast_enabled, 1);
> >  	if (ret == 0)
> >  		vf->promisc_multicast_enabled = TRUE;
> > +	else if (ret == I40E_NOT_SUPPORTED)
> > +		ret = -ENOTSUP;
> >  	else
> >  		ret = -EAGAIN;
> >
> > @@ -2236,6 +2242,8 @@ i40evf_dev_allmulticast_disable(struct rte_eth_dev
> *dev)
> >  	ret = i40evf_config_promisc(dev, vf->promisc_unicast_enabled, 0);
> >  	if (ret == 0)
> >  		vf->promisc_multicast_enabled = FALSE;
> > +	else if (ret == I40E_NOT_SUPPORTED)
> > +		ret = -ENOTSUP;
> >  	else
> >  		ret = -EAGAIN;
> >
> >