Re: [PATCH net-next RFC v3] net: hdlc_x25: Queue outgoing LAPB frames

[Xie He]

On Mon, Feb 15, 2021 at 1:25 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> > +     /* When transmitting data:
> > +      * first we'll remove a pseudo header of 1 byte,
> > +      * then the LAPB module will prepend an LAPB header of at most 3 bytes.
> > +      */
> > +     dev->needed_headroom = 3 - 1;
>
> 3 - 1 = 2
>
> Thanks

Actually this is intentional. It makes the numbers more meaningful.

The compiler should automatically generate the "2" so there would be
no runtime penalty.