Re: [PATCH net] drivers/net/wan/hdlc: In hdlc_rcv, check to make sure dev is an HDLC device

[Xie He]

On Mon, Oct 19, 2020 at 2:22 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> Looks correct to me. I spotted there is also IFF_WAN_HDLC added by
> 7cdc15f5f9db ("WAN: Generic HDLC now uses IFF_WAN_HDLC private flag.")
> would using that flag also be correct and cleaner potentially?
>
> Up to you, just wanted to make sure you considered it.

Oh, Yes! I see IFF_WAN_HDLC is set for all HDLC devices. I also
searched through the kernel code and see no other uses of
IFF_WAN_HDLC. So I think we can use IFF_WAN_HDLC to reliably check if
a device is an HDLC device. This should be cleaner than checking
ndo_start_xmit.

Thanks! I'll change this patch to use IFF_WAN_HDLC.