From owner-freebsd-hackers@FreeBSD.ORG Fri Jul 22 00:25:58 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1744416A420 for ; Fri, 22 Jul 2005 00:25:58 +0000 (GMT) (envelope-from sam@errno.com) Received: from ebb.errno.com (ebb.errno.com [66.127.85.87]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9BFED43D48 for ; Fri, 22 Jul 2005 00:25:57 +0000 (GMT) (envelope-from sam@errno.com) Received: from [66.127.85.91] ([66.127.85.91]) (authenticated bits=0) by ebb.errno.com (8.12.9/8.12.6) with ESMTP id j6M0Ptms039262 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 21 Jul 2005 17:25:56 -0700 (PDT) (envelope-from sam@errno.com) Message-ID: <42E03E5B.80905@errno.com> Date: Thu, 21 Jul 2005 17:31:23 -0700 From: Sam Leffler User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050327) X-Accept-Language: en-us, en MIME-Version: 1.0 To: David Malone References: <200507211849.aa11934@salmon.maths.tcd.ie> In-Reply-To: <200507211849.aa11934@salmon.maths.tcd.ie> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Sam Pierson , FreeBSD Hackers Subject: Re: Atheros, hardware access layer, collisions X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Jul 2005 00:25:58 -0000 David Malone wrote: >>I was looking for this in the ah.h and the ah_desc.h files. Are they >>someplace else, or maybe this is a system call? I can't find anything >>about the retry limit (<-- CWmin = retry?) Thanks, > > > CWmin is a setting that controls the random delay before packets > are transmitted. Search for tqi_cwmin in the driver. The retry limit > says how many times the MAC should retry if it gets a collision > while trying to transmit - I think it is controled by the tqi_shretry > and tqi_lgretry values. In the driver in 6.X you can (in principle) > set these values at the time the transmit queues are configured. You need to set cwmin on the tx q as David describes. Be sure to set the parameters you set into the hardware; check the wme update code for the correct logic. For the other thing just set the tx descriptor to do 1 try. Sam