Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:56114 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752530Ab3DILFQ (ORCPT ); Tue, 9 Apr 2013 07:05:16 -0400 Message-ID: <1365505512.8465.40.camel@jlt4.sipsolutions.net> (sfid-20130409_130520_810272_A7A123BF) Subject: Re: [PATCH] mac80211: always pick a basic rate to tx RTS/CTS for pre-HT rates From: Johannes Berg To: Karl Beldan Cc: linux-wireless , Karl Beldan Date: Tue, 09 Apr 2013 13:05:12 +0200 In-Reply-To: <20130409105535.GA27875@magnum.frso.rivierawaves.com> (sfid-20130409_130003_905842_1241A10F) References: <1365156384-6699-1-git-send-email-karl.beldan@gmail.com> <1365503356.8465.37.camel@jlt4.sipsolutions.net> <20130409105535.GA27875@magnum.frso.rivierawaves.com> (sfid-20130409_130003_905842_1241A10F) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, 2013-04-09 at 12:55 +0200, Karl Beldan wrote: > On Tue, Apr 09, 2013 at 12:29:16PM +0200, Johannes Berg wrote: > > On Fri, 2013-04-05 at 12:06 +0200, Karl Beldan wrote: > > > From: Karl Beldan > > > > > > When the 1st rate control entry is a pre-HT rate we want to set > > > rts_cts_rate_idx "as the fastest basic rate that is not faster than the > > > data rate"(code comments). > > > But in case some bss allowed rate indexes are lower than the lowest bss > > > basic rate, if the rate control selects a rate among the formers for its > > > 1st rate control entry, rts_cts_rate_idx remains 0 and is not a basic > > > rate index. > > > This commit sets rts_cts_rate_idx to the lowest bss basic rate index in > > > this situation. > > > > I guess it's a good thing you're looking at this code. However, I'm not > > sure what you're doing here is correct. In this case, the PHY mandatory > > rates should be used. See 9.7.6.5.2 "Selection of a rate or MCS": > > > Thanks for looking at this. > > You are quoting the chapter for "control _response_ frames" which does > not apply here (even CTS-to-self are not control response frames). Oh, oops, confused. But then you look at 9.7.6.2 "Rate selection for control frames that initiate a TXOP", which just mandates that you use any rate that the receiver supports, so why bother doing basic rates etc. at all? johannes