Subject: Re: [PATCH net-next v5 1/8] octeon_ep_vf: Add driver framework and device initialization

From: Jakub Kicinski <[email-masked]>
Date: Wed, 31 Jan 2024 16:14:06 -0800

On Sun, 28 Jan 2024 21:02:47 -0800 Shinas Rasheed wrote:
> +static int octep_vf_stop(struct net_device *netdev)
> +{
> +	struct octep_vf_device *oct = netdev_priv(netdev);
> +
> +	netdev_info(netdev, "Stopping the device ...\n");
> +
> +	/* Stop Tx from stack */
> +	netif_tx_stop_all_queues(netdev);

netif_tx_disable() stops queues, IIRC. You seem to stop them twice.

> +	netif_carrier_off(netdev);
> +	netif_tx_disable(netdev);

You haven't masked any IRQ or disabled NAPI. What prevents the queues
from getting restarted right after this call?

> +static void octep_vf_tx_timeout(struct net_device *netdev, unsigned int txqueue)
> +{
> +	struct octep_vf_device *oct = netdev_priv(netdev);
> +
> +	queue_work(octep_vf_wq, &oct->tx_timeout_task);
> +}

I don't see you canceling this work. What if someone unregistered
the device before it runs? You gotta netdev_hold() a reference.

> +err_register_dev:
> +err_mbox_version:
> +	octep_vf_delete_mbox(octep_vf_dev);
> +err_setup_mbox:
> +	octep_vf_device_cleanup(octep_vf_dev);
> +err_octep_vf_config:
> +	free_netdev(netdev);
> +err_alloc_netdev:
> +	pci_release_mem_regions(pdev);
> +err_pci_regions:
> +err_dma_mask:
> +	pci_disable_device(pdev);
> +	dev_err(&pdev->dev, "Device probe failed\n");
> +	return err;
> +}

Name the labels after what you're jumping to, please.
It's so much easier to make sure the code is correct that way.

> +static int __init octep_vf_init_module(void)
> +{
> +	int ret;
> +
> +	pr_info("%s: Loading %s ...\n", OCTEP_VF_DRV_NAME, OCTEP_VF_DRV_STRING);
> +
> +	/* work queue for all deferred tasks */
> +	octep_vf_wq = create_singlethread_workqueue(OCTEP_VF_DRV_NAME);

Is there a reason this wq has to be single threaded and different than
system queue? All you schedule on it in this series is the reset task.

> +	if (!octep_vf_wq) {
> +		pr_err("%s: Failed to create common workqueue\n",
> +		       OCTEP_VF_DRV_NAME);
> +		return -ENOMEM;
> +	}
> +
> +	ret = pci_register_driver(&octep_vf_driver);
> +	if (ret < 0) {
> +		pr_err("%s: Failed to register PCI driver; err=%d\n",
> +		       OCTEP_VF_DRV_NAME, ret);
> +		return ret;
> +	}
> +
> +	pr_info("%s: Loaded successfully !\n", OCTEP_VF_DRV_NAME);

One message when driver is loaded is probably fine, but two is really
pushing it. Please don't spam the logs.

> +	return ret;
> +}
-- 
pw-bot: cr