Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:55680 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753801AbdKMRFb (ORCPT ); Mon, 13 Nov 2017 12:05:31 -0500 Subject: Re: Setting single rate in ath10k broken by "reject/clear user rate mask if not usable" To: Johannes Berg , Oleksij Rempel , "linux-wireless@vger.kernel.org" , ath10k , kirtika@google.com References: <13895fa0-3685-dd2b-583d-2d6469d23cfe@candelatech.com> <1507708948.1998.15.camel@sipsolutions.net> <2c293255-aa79-75a0-1c28-994f864cddf4@candelatech.com> <1508312033.2674.9.camel@sipsolutions.net> <2ad42671-59c4-80ed-4bca-f874eb53d653@candelatech.com> <8c2e0e98-f3f4-6e0c-1bf0-43dfa6e97275@rempel-privat.de> <1508358869.2674.55.camel@sipsolutions.net> <9791c86a-a15f-4c99-ab84-ce00b242d70f@candelatech.com> <1508360527.2674.61.camel@sipsolutions.net> <0bfb289d-a9fa-03d9-f9c7-cc0d01b0bd43@candelatech.com> <1508944670.2421.49.camel@sipsolutions.net> <1509135311.2283.12.camel@sipsolutions.net> <1510567783.30497.33.camel@sipsolutions.net> From: Ben Greear Message-ID: (sfid-20171113_180535_253826_D9521AD4) Date: Mon, 13 Nov 2017 09:05:28 -0800 MIME-Version: 1.0 In-Reply-To: <1510567783.30497.33.camel@sipsolutions.net> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 11/13/2017 02:09 AM, Johannes Berg wrote: > On Fri, 2017-10-27 at 13:41 -0700, Ben Greear wrote: > >> ath10k ignores the tx rateset pretty much entirely when sending management >> frames, so even if you set the tx rateset to have only VHT MCS 8, >> management frames are still sent with legacy ratesets. > > So that's a driver bug. The firmware gives the ability to set a single fixed rate for multicast, and another for management frames. It is possibly to set the tx-data frame rate to another fixed rate, or to a more normal rateset. But, you do not have full control over setting tx-data rates (no way to tell stock firmware to use 6Mbps /g rate and mcs 8 (only), for instance). The multicast and mgt frame API is not hooked up in the stock driver as far as I know. But even if they were, I don't see a good way to make this fit with the mac80211 txrate setting framework. What is the suggested approach to propagate a rateset set with 'iw' to a firmware with these limitations? For the Intel firmware NICs, how do they set management and bcast tx rates? >> My end goal about this part is to be able to configure a single tx rate >> and have that be allowed again, at least with ath10k. >> >> Maybe a new flag for drivers like ath10k that at least somewhat ignore >> the tx-rateset for management frames, and this flag would allow us to >> bypass the cannot-set-single-rate check? > > What? No, I'm not going to put a driver bug into the API like that! Thanks for the constructive feedback. --Ben > > johannes > -- Ben Greear Candela Technologies Inc http://www.candelatech.com