Return-path: Received: from nm.newmedia-net.de ([217.113.179.122]:35515 "EHLO webmail.newmedia-net.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbdBLUVy (ORCPT ); Sun, 12 Feb 2017 15:21:54 -0500 To: Ben Greear , Adrian Chadd References: <0082a9e3-83f3-9bc3-af43-b890b91cfd93@candelatech.com> <589F50B8.4020609@candelatech.com> <02b7f70a-7da2-f2e4-8904-bdffc3ca90a1@candelatech.com> <159ba156-cf2d-db0d-a6af-2557b9bfa6b6@dd-wrt.com> Cc: "linux-wireless@vger.kernel.org" , ath10k From: Sebastian Gottschall Message-ID: <3b477278-2418-e436-77ad-449e9d54b60b@dd-wrt.com> (sfid-20170212_212207_597536_DA2C8FFC) Date: Sun, 12 Feb 2017 21:21:45 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Subject: Re: VHT 160Mhz and nss related config. Sender: linux-wireless-owner@vger.kernel.org List-ID: Am 12.02.2017 um 17:05 schrieb Ben Greear: > > > On 02/12/2017 02:56 AM, Sebastian Gottschall wrote: >> Am 11.02.2017 um 20:38 schrieb Ben Greear: >>> On 02/11/2017 10:21 AM, Sebastian Gottschall wrote: >>>> Am 11.02.2017 um 18:58 schrieb Ben Greear: >>>>> On 02/10/2017 08:37 PM, Adrian Chadd wrote: >>>>>> On 10 February 2017 at 20:22, Sebastian Gottschall >>>>>> wrote: >>>>>>> i really can't believe this. if this is true the 160 mhz mode >>>>>>> would not >>>>>>> make any sense. >>>>>>> the maximum tx / rx rate for 4x4 vht80 and 2x2 vht160 is >>>>>>> identical. so >>>>>>> vht160 would not increase performance in any way >>>>>> >>>>>> Well, if it can also do 2x2 MU-MIMO at 160MHz then it can be a >>>>>> perfectly fine STA to a 4x4 160MHz MU-MIMO chip that can actually >>>>>> transmit 2x2 rates to different MU-MIMO peers. >>>>>> >>>>>> That's the outstanding question I have - is it like, 2x2 MU only, or >>>>>> is it say, 2 concurrently different spatial stream 2x2 MU? Ie, >>>>>> can you >>>>>> have 2 peers, different VHT spatial groups (or 4 peers, 1 spatial >>>>>> group each) all going at the same time? >>>>>> >>>>>> I'm .. not even sure how you're supposed to cleanly negotiate >>>>>> that you >>>>>> can do 4NSS in VHT80 but 2NSS in VHT160 to a peer... that only makes >>>>>> sense if you're doing lots of 1NSS and 2NSS MU-MIMO peers.. >>>>> >>>>> I think using the max-rx-rate logic might could imply this, but I >>>>> am not sure >>>>> many drivers fill this out properly. >>>>> >>>>> Looks like a mess waiting to happen to me. >>>>> >>>>> Even if you can do 1x1 160Mhz MU-MIMO to two stations, and I am >>>>> not certain you >>>>> can since in 80Mhz you can only do a 1x1 and a 2x2 (not two 2x2). >>>>> >>>>> So, from what I know currently, 80+80 is not that useful on the >>>>> 9984 NIC... >>>> never tried 80+80 since i need to enhance the channel logic alot in >>>> my firmware code to handle it. would be great enough if vht160 >>>> would work as expected and >>>> i'm not sure right now if it really works, even if the interface >>>> initialized correctly it assocs only with vht80 >>> >>> 160Mhz is really implemented as 80+80 internally it seems, so what I >>> meant is that >>> 160Mhz or 80+80 both have the 2x2 restriction. >> since i have a older fw source. can you give me a hint where you >> found a indication that its just 2x2? > > Look for: > > MAX_SPATIAL_STREAMS_SUPPORTED_AT_160MHZ your findings where correct. frustrating. > > Thanks, > Ben > -- Mit freundlichen Grüssen / Regards Sebastian Gottschall / CTO NewMedia-NET GmbH - DD-WRT Firmensitz: Berliner Ring 101, 64625 Bensheim Registergericht: Amtsgericht Darmstadt, HRB 25473 Geschäftsführer: Peter Steinhäuser, Christian Scheele http://www.dd-wrt.com email: s.gottschall@dd-wrt.com Tel.: +496251-582650 / Fax: +496251-5826565