From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.candelatech.com ([208.74.158.172]:41141 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752121Ab1LTPEA (ORCPT ); Tue, 20 Dec 2011 10:04:00 -0500 Message-ID: <4EF0A3C1.7050302@candelatech.com> (sfid-20111220_160403_194104_D5FE12D9) Date: Tue, 20 Dec 2011 07:03:29 -0800 From: Ben Greear MIME-Version: 1.0 To: Simon Wunderlich CC: linux-wireless@vger.kernel.org, linville@tuxdriver.com, Johannes Berg , Simon Wunderlich , Mathias Kretschmer Subject: Re: [PATCH 1/2] nl80211: add support for mcs masks References: <1324304099-18327-1-git-send-email-siwu@hrz.tu-chemnitz.de> <1324304099-18327-2-git-send-email-siwu@hrz.tu-chemnitz.de> <4EEF5834.8080408@candelatech.com> <20111219211423.GA24764@pandem0nium> In-Reply-To: <20111219211423.GA24764@pandem0nium> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 12/19/2011 01:14 PM, Simon Wunderlich wrote: > Hello Ben, > > On Mon, Dec 19, 2011 at 07:28:52AM -0800, Ben Greear wrote: >> On 12/19/2011 06:14 AM, Simon Wunderlich wrote: >>> Allow to set mcs masks through nl80211. We also allow to set MCS >>> rates but no legacy rates (and vice versa). >> >> Can you not use the ht-caps logic that went in recently? I was able >> to successfully set station MCS rates with it. It only works for >> station devices at this point...but AP support could probably be >> added without too much trouble. > > I have not tried that out yet, but one important side effect we are > using here is to force HT mode, also for No Ack packets which are > usually sent with the lowest (legacy) rate. We are building fixed > links and want to set a fixed HT rate there, and only this rate should > be used whenever possible (and no legacy rates). The ht-caps patch gives the ability to specify the available MCS rates (again, for stations only at this point). I didn't try forcing speeds higher, but I did test that it could force speeds lower. It requires a patch to hostapd that I've posted, but it has not yet been accepted. There is no way to disable legacy rates in the current code, as far as I know. > > As far as I understand, the ht caps overrides will only override > HT configurations, but what I want is to also let the rate matcher > consider HT rates too and to disable legacy rates completely. > > As the mcs masks support has been prepared a long time ago in iw and > mac80211, it did not seem to be the worst idea to finally fill this > gap and implement it. :) I haven't read your patch in detail, and at the least, the ht-caps code would need some additional work to support your needs. So, I'm not sure whether working on top of the ht-caps logic is useful or not. Likely Johannes will have more useful feedback when he gets the time. I will try to read your patch in more detail when I get a chance. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com