Re: [PATCH net] drivers/net/wan/lapbether: Added needed_tailroom

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

On Sat, Aug 8, 2020 at 7:53 PM Xie He <xie.he.0141@gmail.com> wrote:
>
> The underlying Ethernet device may request necessary tailroom to be
> allocated by setting needed_tailroom. This driver should also set
> needed_tailroom to request the tailroom needed by the underlying
> Ethernet device to be allocated.
>
> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
> Cc: Martin Schiller <ms@dev.tdt.de>
> Signed-off-by: Xie He <xie.he.0141@gmail.com>
> ---
>  drivers/net/wan/lapbether.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
> index 1ea15f2123ed..cc297ea9c6ec 100644
> --- a/drivers/net/wan/lapbether.c
> +++ b/drivers/net/wan/lapbether.c
> @@ -340,6 +340,7 @@ static int lapbeth_new_device(struct net_device *dev)
>          */
>         ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
>                                            + dev->needed_headroom;
> +       ndev->needed_tailroom = dev->needed_tailroom;

Does this solve an actual observed bug?

In many ways lapbeth is similar to tunnel devices. This is not common.