Re: [WTF, maintainers] Re: *PING* iwlagn 2.6.35: "BA scd_flow 0 does not match txq_id 10" regression

["Guy, Wey-Yi" <wey-yi.w.guy@intel.com>]

On Wed, 2010-08-25 at 11:42 -0700, Andrew Lutomirski wrote:
> On Tue, Aug 10, 2010 at 7:05 PM, Guy, Wey-Yi <wey-yi.w.guy@intel.com> wrote:
> > Hi Andrew,
> >
> > On Tue, 2010-08-10 at 14:39 -0700, Andrew Lutomirski wrote:
> >> On Mon, Jul 26, 2010 at 4:02 PM, Andrew Lutomirski <luto@mit.edu> wrote:
> >> > There's a regression in 2.6.35 where the connection breaks and iwlagn
> >> > writes a bunch of:
> >> >
> >> > iwlagn 0000:03:00.0: BA scd_flow 0 does not match txq_id 10
> >> >
> >> > This is confirmed [1] and a patch supposedly exists.  Since this
> >> > breaks at least two people's wireless and 2.6.35 is about to be
> >> > released, can we see the patches?
> >> >
> >> > Thanks,
> >> > Andy
> >> >
> >> > [1] http://article.gmane.org/gmane.linux.kernel.wireless.general/53552
> >> >
> >>
> >> This regression was reported on July 21 and confirmed, supposedly with
> >> a patch available, on July 24 (or maybe July 23).  On July 26 I pinged
> >> the list because I'm affected as well.
> >>
> >> It's now August 10 and both 2.6.35 and 2.5.35.1 have been released and
> >> the bug is still there.  WTF happened?  (I admit I haven't actually
> >> tested 2.6.35.1 because it's still compiling, but I see nothing to
> >> suggest that it's been fixed.)
> >>
> >
> > Sorry for the delay, the problem you report is a real problem in our
> > uCode; unfortunately, we still not root cause the real problem yet. The
> > patch I provide previous just a hack and still waiting for our internal
> > validation team to make sure it did not break the overall behaviors.
> >
> > I will submit the patch as soon as I got the report back from our test
> > team; at the meantime, we are very active work on root cause the real
> > problem. Once we have the possible solution, it will be great if you can
> > help us to verify it.
> 
> In case this helps, I just captured the bug starting with
> iwlagn.debug=1 and with the following patch:
> 
> diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
> b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
> index 7d614c4..8583c42 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
> @@ -1300,8 +1300,9 @@ void iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
>         tid = ba_resp->tid;
>         agg = &priv->stations[sta_id].tid[tid].agg;
>         if (unlikely(agg->txq_id != scd_flow)) {
> -               IWL_ERR(priv, "BA scd_flow %d does not match txq_id %d\n",
> -                       scd_flow, agg->txq_id);
> +               IWL_ERR(priv, "BA scd_flow %d does not match txq_id %d
> (sta_id = %d, tid = %d)\n",
> +                       scd_flow, agg->txq_id, sta_id, tid);
> +               //              iwl_force_reset(priv, IWL_FW_RESET);
>                 return;
>         }
> 
> 
> I've attached the dmesg.  Search for 'BA'.
> 
It is an known issue as I mention. we are working on it and sorry for
the delay.

please take a look at commit 735df29a0641d9d8d65117c48ee460284ffcfc05

"Since it is possible happen very often and we do not want to fill the
syslog, so don't enable the logging by default"

Thanks
Wey