Return-path: Received: from ra.tuxdriver.com ([70.61.120.52]:2983 "EHLO ra.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754310AbXKFQsM (ORCPT ); Tue, 6 Nov 2007 11:48:12 -0500 Date: Tue, 6 Nov 2007 11:47:49 -0500 From: "John W. Linville" To: Claudio Matsuoka Cc: linux-wireless@vger.kernel.org, flamingice@sourmilk.net, dsd@gentoo.org, kune@deine-taler.de Subject: Re: RTL8187 rate control problems Message-ID: <20071106164749.GD4440@tuxdriver.com> (sfid-20071106_164829_671476_6A4A06A2) References: <200711061323.16302.claudio@mandriva.com> <20071106164148.GB4440@tuxdriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20071106164148.GB4440@tuxdriver.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: I botched Michael's email address -- please not that when composing your replies (or reply to this message instead)... John On Tue, Nov 06, 2007 at 11:41:48AM -0500, John W. Linville wrote: > On Tue, Nov 06, 2007 at 01:23:16PM -0200, Claudio Matsuoka wrote: > > > I've been reported a problem with RTL8187 working only at very close ranges > > (4-5m) in Linux while the same hardware works at much higher distances in > > Windows. Investigating the problem, I found that it's caused by the mac80211 > > rate control incrementing the bit rate to 54M and never going down because > > the fail counter stays at zero. What would be a good way to check > > transmission retries or failures in the RTL8187 to prevent this problem? Is > > it possible to have a retry count sent to the tx callback so > > status->retry_count could be set accordingly? > > I think you are right -- it looks like rtl8187 never sets > excessive_retries for transmit status. I don't see anything obvious > in the specs that would give us an actual indication of that either, > which probably explains why it is missing. > > The zd1211rw(-mac80211) driver(s) have a mechanism for matching-up > received ACKs with transmitted frames so that they can synthesize the > required excessive_retries data. Probably rtl8186 needs something > similar. Maybe this would even be worth generalizing? > > John > -- > John W. Linville > linville@tuxdriver.com -- John W. Linville linville@tuxdriver.com