Subject: Re: [PATCH] net: ethernet: ti: am65-cpsw: Fix devlink port register sequence

From: Jakub Kicinski <[email-masked]>
Date: Fri, 24 Jun 2022 16:42:34 -0700

On Thu, 23 Jun 2022 10:13:37 +0530 Siddharth Vadapalli wrote:
> Renaming interfaces using udevd depends on the interface being registered
> before its netdev is registered. Otherwise, udevd reads an empty
> phys_port_name value, resulting in the interface not being renamed.
> 
> Fix this by registering the interface before registering its netdev
> by invoking am65_cpsw_nuss_register_devlink() before invoking
> register_netdev() for the interface.
> 
> Signed-off-by: Siddharth Vadapalli <[email-masked]>

Please add a Fixes tag and [PATCH net] in the subject.

> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> index fb92d4c1547d..47a6c4e5360b 100644
> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> @@ -2527,6 +2527,10 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>  		return ret;
>  	}
>  
> +	ret = am65_cpsw_nuss_register_devlink(common);
> +	if (ret)
> +		goto err_cleanup_ndev;

You need to take the devlink_port_type_eth_set() out of this function
if it's now called before netdev registration and call it after netdev
registration. Otherwise devlink will generate a netlink notification
about the port state change with a half-initialized netdev.

>  	for (i = 0; i < common->port_num; i++) {
>  		port = &common->ports[i];
>  
> @@ -2545,17 +2549,12 @@ static int am65_cpsw_nuss_register_ndevs(struct am65_cpsw_common *common)
>  	if (ret)
>  		goto err_cleanup_ndev;
>  
> -	ret = am65_cpsw_nuss_register_devlink(common);
> -	if (ret)
> -		goto clean_unregister_notifiers;
> -
>  	/* can't auto unregister ndev using devm_add_action() due to
>  	 * devres release sequence in DD core for DMA
>  	 */
>  
>  	return 0;
> -clean_unregister_notifiers:
> -	am65_cpsw_unregister_notifiers(common);
> +
>  err_cleanup_ndev:
>  	am65_cpsw_nuss_cleanup_ndev(common);
>