Re: [PATCH RFC net-next 12/23] net: dsa: lantiq_gswip: support 4k VLANs on API 2.2 or later

[Sverdlin, Alexander]

Hi Daniel,

On Sat, 2025-08-16 at 20:53 +0100, Daniel Golle wrote:
> Dynamically allocate vlans array depending on the switch API version.
> Versions less than 2.2 support 64 VLANs, versions 2.2 or later support
> 4096 VLANs.

...

> @@ -725,9 +730,9 @@ static int gswip_vlan_active_create(struct gswip_priv *priv,
>  		return err;
>  	}
>  
> -	priv->vlans[idx].bridge = bridge;
> -	priv->vlans[idx].vid = vid;
> -	priv->vlans[idx].fid = fid;
> +	(*priv->vlans)[idx].bridge = bridge;
> +	(*priv->vlans)[idx].vid = vid;
> +	(*priv->vlans)[idx].fid = fid;

Would it be possible to leave this chunk unchanged (and all array
dereferencing in the driver as well)?


> @@ -1948,6 +1953,22 @@ static int gswip_validate_cpu_port(struct dsa_switch *ds)
>  	return 0;
>  }
>  
> +static int gswip_allocate_vlans(struct gswip_priv *priv)
> +{
> +	if (GSWIP_VERSION_GE(priv, GSWIP_VERSION_2_2))
> +		priv->num_vlans = 4096;
> +	else
> +		priv->num_vlans = 64;
> +
> +	priv->vlans = devm_kcalloc(priv->dev, priv->num_vlans,
> +				   sizeof((*priv->vlans)[0]), GFP_KERNEL);

maybe sizeof(*priv->vlans) or sizeof(priv->vlans[0])?

> --- a/drivers/net/dsa/lantiq_gswip.h
> +++ b/drivers/net/dsa/lantiq_gswip.h
> @@ -269,7 +270,8 @@ struct gswip_priv {
>  	struct dsa_switch *ds;
>  	struct device *dev;
>  	struct regmap *rcu_regmap;
> -	struct gswip_vlan vlans[64];
> +	struct gswip_vlan (*vlans)[];

... if this would be just "struct gswip_vlan *vlans;"?

> +	unsigned int num_vlans;
>  	int num_gphy_fw;
>  	struct gswip_gphy_fw *gphy_fw;
>  	u32 port_vlan_filter;

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com