Re: [PATCH v2] net: stmmac: skip VLAN restore when VLAN hash ops are missing

[Maxime Chevallier]

Hi,

On 21/03/2026 06:38, 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.
> 
> Check presence of VLAN HW FILTER flags before stmmac_vlan_update().
> 
> Tested on Orange Pi Zero 3.
> 
> Fixes: bd7ad51253a7 ("net: stmmac: Fix VLAN HW state restore")
> Signed-off-by: Michal Piekos <michal.piekos@xxxxxxxxxxxxx>
> ---
> 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. 

I've been seeing the same message on socfpga. My two cents on that is
that this error messages doesn't bring anything to the table anyways.

As Russell explains, it's either triggered when the vlan op isn't
implemented (the stmmac callback macro stuff turns that into a -EINVAL),
or when some capabilities arent present. All in all, it's always stuff
that users can't really do anything about, as it's HW limitations, I
think we can simply discard this message.

Also, nothing actually checks what stmmac_vlan_restore() returns, so we
might as well return void ?

Maxime

> ---
> 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@xxxxxxxxxxxxx
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 6827c99bde8c..cfc0ce9cec9c 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -6863,7 +6863,8 @@ static int stmmac_vlan_restore(struct stmmac_priv *priv)
>  {
>  	int ret;
>  
> -	if (!(priv->dev->features & NETIF_F_VLAN_FEATURES))
> +	if (!(priv->dev->features &
> +	      (NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_VLAN_STAG_FILTER)))
>  		return 0;
>  
>  	if (priv->hw->num_vlan)
> 
> ---
> base-commit: 42bddab0563fe67882b2722620a66dd98c8dbf33
> change-id: 20260314-vlan-restore-error-f8b3a1c7f50a
> 
> Best regards,