RE: [PATCH net-next] [RFC] dpaa2-eth: Move DPAA2 Ethernet driver from staging to drivers/net

[Ioana Ciocoi Radulescu]

> -----Original Message-----
> From: Andrew Lunn [mailto:andrew@xxxxxxx]
> Sent: Friday, August 3, 2018 7:43 PM
> To: Ioana Ciocoi Radulescu <ruxandra.radulescu@xxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx;
> gregkh@xxxxxxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Ioana Ciornei <ioana.ciornei@xxxxxxx>; Laurentiu
> Tudor <laurentiu.tudor@xxxxxxx>; Madalin-cristian Bucur
> <madalin.bucur@xxxxxxx>; Horia Geanta <horia.geanta@xxxxxxx>
> Subject: Re: [PATCH net-next] [RFC] dpaa2-eth: Move DPAA2 Ethernet driver
> from staging to drivers/net
> 
> > +static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev)
> > +{
> > +	struct device *dev;
> > +	struct net_device *net_dev = NULL;
> > +	struct dpaa2_eth_priv *priv = NULL;
> > +	int err = 0;
> > +
> > +	dev = &dpni_dev->dev;
> > +
> > +	/* Net device */
> > +	net_dev = alloc_etherdev_mq(sizeof(*priv),
> DPAA2_ETH_MAX_TX_QUEUES);
> > +	if (!net_dev) {
> > +		dev_err(dev, "alloc_etherdev_mq() failed\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	SET_NETDEV_DEV(net_dev, dev);
> > +	dev_set_drvdata(dev, net_dev);
> > +
> > +	priv = netdev_priv(net_dev);
> > +	priv->net_dev = net_dev;
> > +
> > +	priv->iommu_domain = iommu_get_domain_for_dev(dev);
> > +
> > +	/* Obtain a MC portal */
> > +	err = fsl_mc_portal_allocate(dpni_dev,
> FSL_MC_IO_ATOMIC_CONTEXT_PORTAL,
> > +				     &priv->mc_io);
> > +	if (err) {
> > +		if (err == -ENXIO)
> > +			err = -EPROBE_DEFER;
> > +		else
> > +			dev_err(dev, "MC portal allocation failed\n");
> > +		goto err_portal_alloc;
> > +	}
> > +
> > +	/* MC objects initialization and configuration */
> > +	err = setup_dpni(dpni_dev);
> > +	if (err)
> > +		goto err_dpni_setup;
> > +
> > +	err = setup_dpio(priv);
> > +	if (err)
> > +		goto err_dpio_setup;
> > +
> > +	setup_fqs(priv);
> > +
> > +	err = setup_dpbp(priv);
> > +	if (err)
> > +		goto err_dpbp_setup;
> > +
> > +	err = bind_dpni(priv);
> > +	if (err)
> > +		goto err_bind;
> > +
> > +	/* Add a NAPI context for each channel */
> > +	add_ch_napi(priv);
> > +
> > +	/* Percpu statistics */
> > +	priv->percpu_stats = alloc_percpu(*priv->percpu_stats);
> > +	if (!priv->percpu_stats) {
> > +		dev_err(dev, "alloc_percpu(percpu_stats) failed\n");
> > +		err = -ENOMEM;
> > +		goto err_alloc_percpu_stats;
> > +	}
> > +	priv->percpu_extras = alloc_percpu(*priv->percpu_extras);
> > +	if (!priv->percpu_extras) {
> > +		dev_err(dev, "alloc_percpu(percpu_extras) failed\n");
> > +		err = -ENOMEM;
> > +		goto err_alloc_percpu_extras;
> > +	}
> > +
> > +	err = netdev_init(net_dev);
> > +	if (err)
> > +		goto err_netdev_init;
> 
> At the end of netdev_init() you call netdev_register(). From that
> point on, you device is live. Its .ndo's can be called....
> 
> > +
> > +	/* Configure checksum offload based on current interface flags */
> > +	err = set_rx_csum(priv, !!(net_dev->features & NETIF_F_RXCSUM));
> > +	if (err)
> > +		goto err_csum;
> > +
> > +	err = set_tx_csum(priv, !!(net_dev->features &
> > +				   (NETIF_F_IP_CSUM |
> NETIF_F_IPV6_CSUM)));
> > +	if (err)
> > +		goto err_csum;
> > +
> > +	err = alloc_rings(priv);
> > +	if (err)
> > +		goto err_alloc_rings;
> 
> How well does the device work if it has not allocated the rings yet,
> when it is asked to do something?
> 
> > +
> > +	net_dev->ethtool_ops = &dpaa2_ethtool_ops;
> > +
> > +	err = setup_irqs(dpni_dev);
> 
> How well do it work without interrupts being set up?
> 
> > +	if (err) {
> > +		netdev_warn(net_dev, "Failed to set link interrupt, fall back
> to polling\n");
> > +		priv->poll_thread = kthread_run(poll_link_state, priv,
> > +						"%s_poll_link", net_dev-
> >name);
> > +		if (IS_ERR(priv->poll_thread)) {
> > +			netdev_err(net_dev, "Error starting polling
> thread\n");
> > +			goto err_poll_thread;
> > +		}
> > +		priv->do_link_poll = true;
> > +	}
> 
> Probably the correct place to register the netdev is here.

Good point, I'll fix it in v2.

Thanks a lot,
Ioana