Re: Regarding A-MPDU status field

[David Young <dyoung-e+AXbWqSrlAAvxtiuMwx3w@public.gmane.org>]

On Tue, Nov 22, 2011 at 02:27:17PM +0000, Rao, Krishna wrote:
> Hi,
> 
> >>> 4) (Debatable) Delimiter CRC value itself. I don't know if there is
> >>> any hardware which returns the actual value to software. Anyway,
> >>> having it as part of the field will allow platforms which do possess
> >>> the capability, to provide this information. It may come in handy for
> >>> some users.
> >> 
> >> That seems a bit of a stretch, but it's only 8 bits so I wouldn't mind
> >> adding it.
> >
> >I think that in the interest of, as you say, "reconstruct[ing] what
> >happened on the air as precisely as possible", which is a goal that I
> >strongly agree with, it is important to pass that information up.
> >
> >On the other hand, if the information is only hypothetically
> >available....
> Since there is always a possibility that some existing or future
> hardware might have this capability, having this subfield in the
> specification might prove useful down the line. Inviting comments on
> this.

Still thinking along the lines of "reconstruct ... as precisely", let me
throw this idea out there: the A-MPDU field can help us to reconstruct a
whole A-MPDU by telling us the range of byte indices where the subframe
may have begun in the aggregate, [start0, start1].  If the driver
doesn't know, then the interval is [0, length of A-MPDU].  If the driver
knows precisely, then [x, x], otherwise [x, y] where x != y.

Dave

-- 
David Young
dyoung-e+AXbWqSrlAAvxtiuMwx3w@public.gmane.org    Urbana, IL    (217) 721-9981