Return-path: Received: from nbd.name ([46.4.11.11]:52909 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751521Ab2A1Svm (ORCPT ); Sat, 28 Jan 2012 13:51:42 -0500 Message-ID: <4F2443BB.3000602@openwrt.org> (sfid-20120128_195204_095223_457C6A73) Date: Sat, 28 Jan 2012 19:51:39 +0100 From: Felix Fietkau MIME-Version: 1.0 To: Marek Lindner CC: linux-wireless@vger.kernel.org Subject: Re: [PATCH] mac80211: minstrel_ht should not override user supplied rts setting References: <1327735027-30121-1-git-send-email-lindner_marek@yahoo.de> <1327735027-30121-2-git-send-email-lindner_marek@yahoo.de> <4F23F753.8070405@openwrt.org> <201201290243.47953.lindner_marek@yahoo.de> In-Reply-To: <201201290243.47953.lindner_marek@yahoo.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2012-01-28 7:43 PM, Marek Lindner wrote: > On Saturday, January 28, 2012 21:25:39 Felix Fietkau wrote: >> On 2012-01-28 8:17 AM, Marek Lindner wrote: >> > Signed-off-by: Marek Lindner >> >> NACK, minstrel_ht sets RTS/CTS only from the second rate retry slot on, >> to increase the success probability during retransmissions. For the >> first slot, it is unset. The user supplied rts setting is not suitable >> for configuring RTS/CTS usage this way, so if you want to disable it >> entirely, you'd need to add a new setting for that. > > If you think it is unsuitable do you mind elaborating what this setting is > for? As far as I can tell minstrel_ht is the only rate control algorithm that > decides to be smarter than the user configuring the device. Without mentioning > this anywhere! IMHO it should be minstrel_ht explaining why this makes sense, > not the other way round. The user configurable RTS/CTS setting sets a threshold which is applied to all transmission attempts with a packet size above it. What minstrel_ht does is enable RTS/CTS only for on-chip retransmissions of the second rate slot and below. That means as long as it doesn't fall back to lower rates, no RTS/CTS gets used. It's not about minstrel_ht being smarter than the user. It's about adaptive control of RTS/CTS being smarter than a static setting. - Felix