Re: [2.6.27-rc7 vs 2.6.29 Regresion] Wifi Network Slownes rt2500pci

[Ivo van Doorn <ivdoorn@gmail.com>]

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On Monday 25 May 2009, Alejandro Riveira Fernández wrote:
> El lun, 25-05-2009 a las 13:23 +0200, Ivo van Doorn escribió:
> > On Monday 25 May 2009, Alejandro Riveira Fernández wrote:
> > > I reported it previously but i'm resending it as a regresion
> > > 
> > > More info on the bugzilla
> > > 
> > >  http://bugzilla.kernel.org/show_bug.cgi?id=13362
> > > 
> > > I bisected it in the estable tree (it regresses too) and the revert
> > > helps there but reverting the upstream commit in mainline does not help
> > > to fix it completely...
> > 
> > Bug 9273 -  rt2500pci: low TCP throughput
> > 	http://bugzilla.kernel.org/show_bug.cgi?id=9273
> > 
> > Bug 443203 -  Fedora rawhide + ralink = slow bit rate
> > 	https://bugzilla.redhat.com/show_bug.cgi?id=443203
> > 
> > [Hardy][Intrepid] Low bandwidth with rt2400 / rt2500 drivers
> > 	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/190515
> > 
> > I can't call this a regression, dozens people have reported the problems
> > ranging from kernels 2.6.25 to 2.6.29. Perhaps in your case it worked slightly
> > better once, but that was not the case for all other users.
> > 
> > Have you tried the "iwconfig wlan0 rate54M" workaround?
> 
>    Yep during various releases I used that workaround but once I
> switched to minstrel rate choosing alg (that's the neme isn't it) the
> problem gone away and i got allways a good connection for several
> releases and many kernels tried; till this patch. If I revert this patch
> the problem goes away completly and reliably (i'm using 2.6.29.4 with
> the patch reveted) so something has clearly regressed for me.
> 
>  You can see my coments ( ariveira ) on rt2x00 forums regarding the
> issues you mention (low speed that gets fixed forcing the rate) in the
> long thread about rt2500pci low rate[1].
>  
>  Checking the message i see that it was 2.6.27  when i began using
> minstrel and got a rock solid connection in 2.6.27.x, 2.6.28.x and
> 2.6.29 minus 64e1b00c974ddeae6a60ebb02e1c487371905cea
> 
>  The problem is not that I get a low rate on connect (1Mbit) that i can
> easily fix with iwconfig the problem is that with 54M (and 48M and the
> like) connections I get a bumpy and low speed connection.
>  
> So I honesty think it is not the same issue and I hope you read this as
> an interesting data point and not just as a duplicate.
> 
> Would the output of this script[2] for 2.6.29.4 with and without the
> revert help you ?

Yes please try it. but for 2.6.29 you probably need attached script instead.
I am not sure if it would produce something useful, because I think Johannes
assertion is right. With his patch the correct bitmask is send to the driver
and the driver actually needs _that_ bitmask without any editing
(rather then the incorrect one which was send before that patch).

Ivo

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