Block ACK in Ralink RT2860

[Ramanujan Seshadri]

I am testing the driver code witht he ralink nic.  Yes the frame
aggregation works, since i get higher throughput.  I am actually tryign to
know how many frames (MPDU's) are aggregated each time in an AMPDU.

Regarding the MPDU density - i was wondering how it should affect the Frame
aggregation. Since MPDU density is the time duration between each MPDU sent
within the AMPDU.  So, how does this matter to the hardware for aggregating
the number of frames. It just sends MPDU's with the set interval.

The other two limits make sense, the BAWinSize and the MAX_LEN_CFG.

Ram

On Wed, Jan 30, 2013 at 5:45 PM, PseudoCylon <moonlightakkiy at yahoo.ca>wrote:

> On Wed, Jan 30, 2013 at 1:20 PM, Ramanujan Seshadri
> <ksramanujan at gmail.com> wrote:
> > Thank you. I also wanted to know the function where the Block ACK Window
> > will be decided. is it decided during the ADDBA session establishment or
> > does it change dynamically.
>
> The hardware will aggregate packets until any of following limits hit max
> http://fxr.watson.org/fxr/source/dev/ral/rt2860reg.h#L782
> * rt2860_txwi.flags
>         RT2860_TX_MPDU_DSITY_SHIFT
>         000 == no restriction
>         001 == 1/4 us
>         010 == 1/2 us
>         ...
>         111 == 16 us
> * rt2860_txwi.xflags
>         RT2860_TX_BAWINSIZE_SHIFT (frame count)
>
> http://fxr.watson.org/fxr/source/dev/ral/rt2860reg.h#L93
> * RT2860_MAX_LEN_CFG bit 12:13
>         00 == 8k bytes
>         01 == 16k
>         10 == 32k
>         11 == 64k
>
> At a quick look, none of them is set in current code. Also,
> RT2860_TX_AMPDU flag need to be set to make the h/w aggregate packets.
>
> How is ampdu working on ral(4)? I cannot test because I do not have
> any ral(4) nic (only have run(4) nics).
>
>
> AK
>
> >
> >
> > On Thu, Jan 24, 2013 at 5:13 PM, PseudoCylon <moonlightakkiy at yahoo.ca>
> > wrote:
> >>
> >> > Message: 6
> >> > Date: Thu, 24 Jan 2013 12:23:55 -0500
> >> > From: Ramanujan Seshadri <ksramanujan at gmail.com>
> >> > To: freebsd-net at freebsd.org
> >> > Subject: Block ACK in Ralink RT2860
> >> > Message-ID:
> >> >
> >> > <CAK=C58KyA80kgVqenHj8xEkmkKDNHnmbQkZoyKQ-K6r_7V4GGA at mail.gmail.com>
> >> > Content-Type: text/plain; charset=ISO-8859-1
> >> >
> >> > Hi all,
> >> > I am trying  to read the contents of block ack's in a Ralink RT2860
> >> > driver.
> >> > Can you please help me to know which function i should be looking
> into ?
> >>
> >> At default, all BA packets are dropped by h/w. Clear RT2860_DROP_BA flag
> >> at
> >> http://fxr.watson.org/fxr/source/dev/ral/rt2860.c#L3559
> >>
> >> Then, the diver should receive BA packets, and you can read them.
> >>
> >>
> >> AK
> >
> >
>