A small fix for if_em.c, if_igb.c, if_ixgbe.c

[Jack Vogel]

Hey Adrian,

Didn't want you to think I was ignoring you, just kind of in the middle of
some deadline issues and was not able to give this a lot of cycles.

I've been reading the email seeing if some kind of consensus was formed,
so far I'm not strongly convinced what's right. Does someone feel there is
an urgent need to get this changed?

Cheers,

Jack



On Mon, Dec 9, 2013 at 11:37 AM, Adrian Chadd <adrian at freebsd.org> wrote:

> Jack / John - thoughts?
>
>
> -a
>
> On 8 December 2013 19:44, Adrian Chadd <adrian at freebsd.org> wrote:
> > .. I'm saying that we should have if_transmit( )return an error only
> > on the current packet, and 0 if it was queued.
> >
> > We don't have a mechanism to say that a queued packet actually made it
> > onto the wire. Whether we should is a different discussion.
> >
> > Ie, after thinking about this some more, I'd like to:
> >
> > * change if_transmit in these drivers to do exactly what you suggest -
> > it should return an error only if the given packet couldn't be queued.
> > It shouldn't matter whether it is later transmitted or not - we don't
> > have a feedback mechanism for that.
> > * figure out a very specific definition of what xxx_mq_start_locked()
> > should return - my gut feeling is an error if it couldn't queue a
> > frame, and 0 if it dispatched a frame to the hardware - and then make
> > the code match this definition.
> >
> >
> >
> > -adrian
>