Re: [PATCH v3] net: stmmac: skip VLAN restore when VLAN hash ops are missing

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Sat, Mar 28, 2026 at 07:51:53AM +0100, Michal Piekos wrote:
> stmmac_vlan_restore() unconditionally calls stmmac_vlan_update() when
> NETIF_F_VLAN_FEATURES is set. On platforms where priv->hw->vlan (or
> ->update_vlan_hash) is not provided, stmmac_update_vlan_hash() returns
> -EINVAL via stmmac_do_void_callback(), resulting in a spurious
> "Failed to restore VLANs" error even when no VLAN filtering is in use.
> 
> Remove the unneeded comment.
> 
> Tested on Orange Pi Zero 3.
> 
> Fixes: bd7ad51253a7 ("net: stmmac: Fix VLAN HW state restore")
> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> ---
> This patch fixes a noisy "Failed to restore VLANs" message on platforms
> where stmmac VLAN hash ops are not implemented.
> stmmac_vlan_restore() calls stmmac_vlan_update() without checking for
> VLAN hash ops presence which results in -EINVAL. 
> ---
> Changes in v3:
> - Remove the offending comment
> - Restore the original check for NETIF_F_VLAN_FEATURES
> - Link to v2: https://lore.kernel.org/r/20260321-vlan-restore-error-v2-1-45cf56a5223d@mmpsystems.pl
> 
> Changes in v2:
> - Replace check for hash ops with check for HW FILTER flags
> - Link to v1: https://lore.kernel.org/r/20260314-vlan-restore-error-v1-1-4fc6c3e2115f@mmpsystems.pl
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 6827c99bde8c..0f3e5ac05faa 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -6861,19 +6861,13 @@ static int stmmac_vlan_rx_kill_vid(struct net_device *ndev, __be16 proto, u16 vi
>  
>  static int stmmac_vlan_restore(struct stmmac_priv *priv)
>  {
> -	int ret;
> -
>  	if (!(priv->dev->features & NETIF_F_VLAN_FEATURES))
>  		return 0;
>  
>  	if (priv->hw->num_vlan)
>  		stmmac_restore_hw_vlan_rx_fltr(priv, priv->dev, priv->hw);
>  
> -	ret = stmmac_vlan_update(priv, priv->num_double_vlans);
> -	if (ret)
> -		netdev_err(priv->dev, "Failed to restore VLANs\n");
> -
> -	return ret;
> +	return stmmac_vlan_update(priv, priv->num_double_vlans);
>  }

Yes, but as both Andrew and myself have pointed out, no one checks
the return value of stmmac_vlan_restore(), so why does it return
int?

-- 
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