Re: [Intel-wired-lan] [PATCH iwl-net] idpf: check error for register_netdev() on init

[Simon Horman <horms@kernel.org>]

On Mon, Feb 10, 2025 at 06:38:51PM -0800, Emil Tantilov wrote:
> Current init logic ignores the error code from register_netdev(),
> which will cause WARN_ON() on attempt to unregister it, if there was one,
> and there is no info for the user that the creation of the netdev failed.
> 
> WARNING: CPU: 89 PID: 6902 at net/core/dev.c:11512 unregister_netdevice_many_notify+0x211/0x1a10
> ...
> [ 3707.563641]  unregister_netdev+0x1c/0x30
> [ 3707.563656]  idpf_vport_dealloc+0x5cf/0xce0 [idpf]
> [ 3707.563684]  idpf_deinit_task+0xef/0x160 [idpf]
> [ 3707.563712]  idpf_vc_core_deinit+0x84/0x320 [idpf]
> [ 3707.563739]  idpf_remove+0xbf/0x780 [idpf]
> [ 3707.563769]  pci_device_remove+0xab/0x1e0
> [ 3707.563786]  device_release_driver_internal+0x371/0x530
> [ 3707.563803]  driver_detach+0xbf/0x180
> [ 3707.563816]  bus_remove_driver+0x11b/0x2a0
> [ 3707.563829]  pci_unregister_driver+0x2a/0x250
> 
> Introduce an error check and log the vport number and error code.
> On removal make sure to check VPORT_REG_NETDEV flag prior to calling
> unregister and free on the netdev.
> 
> Add local variables for idx, vport_config and netdev for readability.
> 
> Fixes: 0fe45467a104 ("idpf: add create vport and netdev configuration")
> Reviewed-by: Madhu Chittim <madhu.chittim@intel.com>
> Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com>
> Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
> ---
>  drivers/net/ethernet/intel/idpf/idpf_lib.c | 27 ++++++++++++++--------
>  1 file changed, 18 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c

...

> @@ -1536,12 +1540,17 @@ void idpf_init_task(struct work_struct *work)
>  	}
>  
>  	for (index = 0; index < adapter->max_vports; index++) {
> -		if (adapter->netdevs[index] &&
> -		    !test_bit(IDPF_VPORT_REG_NETDEV,
> -			      adapter->vport_config[index]->flags)) {
> -			register_netdev(adapter->netdevs[index]);
> -			set_bit(IDPF_VPORT_REG_NETDEV,
> -				adapter->vport_config[index]->flags);
> +		struct idpf_vport_config *vport_config = adapter->vport_config[index];
> +		struct net_device *netdev = adapter->netdevs[index];
> +
> +		if (netdev && !test_bit(IDPF_VPORT_REG_NETDEV, vport_config->flags)) {
> +			err = register_netdev(netdev);
> +			if (err) {
> +				dev_err(&pdev->dev, "failed to register netdev for vport %d: %pe\n",
> +					index, ERR_PTR(err));
> +				continue;
> +			}
> +			set_bit(IDPF_VPORT_REG_NETDEV, vport_config->flags);
>  		}
>  	}

Hi Emil,

I'm wondering if we could reduce indentation and lines longer
than 80 characters in the above like this (completely untested!):


	for (index = 0; index < adapter->max_vports; index++) {
		struct idpf_vport_config *vport_config = adapter->vport_config[index];
		struct net_device *netdev = adapter->netdevs[index];

		if (!netdev ||
		    test_bit(IDPF_VPORT_REG_NETDEV, vport_config->flags))
		    continue;

		err = register_netdev(netdev);
		if (err) {
			dev_err(&pdev->dev, "failed to register netdev for vport %d: %pe\n",
				index, ERR_PTR(err));
			continue;
		}
		set_bit(IDPF_VPORT_REG_NETDEV, vport_config->flags);
	}