if_ral regression

[Weongyo Jeong]

On Wed, Jan 02, 2008 at 09:28:30PM +0800, Sepherosa Ziehau wrote:
> On Jan 2, 2008 10:38 AM, Weongyo Jeong <weongyo.jeong at gmail.com> wrote:
> >
> > > Even with these in place in dfly, I still have strange TX performance
> > > regression in sta mode (drop from 20Mb/s to 3Mb/s under very well
> > > condition) on certain hardwares after 20sec~30sec TCP_STREAM netperf
> > > testing; didn't have enough time to dig, however, all of the tested
> > > hardwares stayed connected during testing (I usually run netperf
> > > stream test for 12 hours or more).
> >
> > I also saw some regression in TX performance during porting malo(4).
> 
> Have you tried to turn bgscan off completely?  My problem seems to be
> hardware (I suspect rf) related.  The TX performance regression does
> not happen with UDP stream which only uses 802.11 ack, i.e. hardware
> seems to have touble to switch between data RX and data TX at high
> freq.

Oops.  It seems this problem is a different one because I always
encounter system crashes (I can't enter DDB, no keyboard works and no
messages on screen) within a hour with HEAD when I tested netperf(1) TX
tests using malo(4) that the tested driver was never crashed before
during testing netperf(1) tests for several hours.  Before 1~2 months
ago, it wasn't happen.   It looks weird and I'm also going to dig it.

> > Problems were fixed after removing following lines in *_start:
> >
> >                         /*
> >                          * Cancel any background scan.
> >                          */
> >                         if (ic->ic_flags & IEEE80211_F_SCAN)
> >                                 ieee80211_cancel_scan(ic);
> >
> > and (optionally)
> >
> >                 if (m->m_flags & M_TXCB)
> >                         ...
> >                         ieee80211_process_callback(ni, m, 0);   /* XXX status?
> >                         ...
> 
> I don't think you can remove TXCB processing in drivers :)

Yes, indeed. :-)

regards,
Weongyo Jeong