[PATCH net] net: airoha: Fix max TX packet length configuration

[Paolo Abeni]

On 4/12/26 10:09 AM, Lorenzo Bianconi wrote:
> According to the Airoha documentation, REG_GDM_LEN_CFG() register does not
> include FCS length. Fix MTU configuration removing ETH_FCS_LEN from
> maximum TX packet length configuration.
> 
> Fixes: 54d989d58d2ac ("net: airoha: Move min/max packet len configuration in airoha_dev_open()")
> Fixes: 03b1b69f0662c ("net: airoha: Introduce airoha_dev_change_mtu callback")
> Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
> ---
>  drivers/net/ethernet/airoha/airoha_eth.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> index c14cdce588a7..a81ffda72b39 100644
> --- a/drivers/net/ethernet/airoha/airoha_eth.c
> +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> @@ -1629,9 +1629,9 @@ static void airoha_update_hw_stats(struct airoha_gdm_port *port)
>  
>  static int airoha_dev_open(struct net_device *dev)
>  {
> -	int err, len = ETH_HLEN + dev->mtu + ETH_FCS_LEN;
>  	struct airoha_gdm_port *port = netdev_priv(dev);
>  	struct airoha_qdma *qdma = port->qdma;
> +	int err, len = ETH_HLEN + dev->mtu;

Sashiko noted that the above may cause regressions, dropping max MTU
vlan frames.

/P