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	Wed, 12 Nov 2008 19:06:19 -0500
Date: Thu, 13 Nov 2008 00:06:16 +0000 (GMT)
From: Hin-Tak Leung <hintak_leung@yahoo.co.uk>
Subject: Re: throughput problem/bisect with rtl8187B
To: Herton Ronaldo Krzesinski <herton@mandriva.com.br>,
	Larry Finger <Larry.Finger@lwfinger.net>
Cc: linux-wireless@vger.kernel.org
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--- On Wed, 12/11/08, Larry Finger <Larry.Finger@lwfinger.net> wrote:
> Herton Ronaldo Krzesinski wrote:
> > Ok, Looks like sifs or eifs setting then expect values
> in another format or
> > have a different meaning may be (or just cause some hw
> bug), it's strange,
> > I suspect sifs value is the culprit. In the patch I
> just reverted to values vendor
> > driver uses, in it difs remains the same, just eifs
> isn't changed for short slot
> > case and kept with a default value (along with what is
> supposed to be ack
> > timeout register), and sifs set to 0x22. Please try
> just the following change
> > to isolate that the SIFS setting caused the throughput
> issue:
> > 
> > diff --git
> a/drivers/net/wireless/rtl818x/rtl8187_dev.c
> b/drivers/net/wireless/rtl818x/rtl8187_dev.c
> > index d49f2a7..c0392e4 100644
> > --- a/drivers/net/wireless/rtl818x/rtl8187_dev.c
> > +++ b/drivers/net/wireless/rtl818x/rtl8187_dev.c
> > @@ -924,7 +924,7 @@ static void
> rtl8187_conf_erp(struct rtl8187_priv *priv, bool
> use_short_slot,
> >  			difs = 0x32;
> >  			eifs = 0x5b;
> >  		}
> > -		rtl818x_iowrite8(priv, &priv->map->SIFS,
> 0xa);
> > +		rtl818x_iowrite8(priv, &priv->map->SIFS,
> 0x22);
> >  		rtl818x_iowrite8(priv, &priv->map->SLOT,
> slot_time);
> >  		rtl818x_iowrite8(priv, &priv->map->DIFS,
> difs);
> 
> This patch gives me the best performance yet. I get about
> 1.0 MB/s download and
> 580 KB/s upload with a 25 MB file using sftp.

Yes, confirming this one number fixes the throughput problem I had. And I can also confirm that wireless-testing + this oneliner seems to be better than 2.6.27. 

I tried it alone on top of wireless-testing, and together with 
the conf_tx and feedback patches.

Thanks for putting time into this!

Hin-Tak