Return-path: Received: from mail2.candelatech.com ([208.74.158.173]:47938 "EHLO mail2.candelatech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752232AbdBMT4d (ORCPT ); Mon, 13 Feb 2017 14:56:33 -0500 Subject: Re: VHT 160Mhz and nss related config. To: Sebastian Gottschall , Adrian Chadd References: <0082a9e3-83f3-9bc3-af43-b890b91cfd93@candelatech.com> <589F50B8.4020609@candelatech.com> Cc: "linux-wireless@vger.kernel.org" , ath10k From: Ben Greear Message-ID: <36c7dfa2-b39c-ad7a-5e39-3daf8983ed2f@candelatech.com> (sfid-20170213_205636_736508_C31625B0) Date: Mon, 13 Feb 2017 11:56:32 -0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 Looks like it is working with the hack I posted: Station 04:f0:21:2e:49:65 (on wlan2) inactive time: 0 ms rx bytes: 64902998 rx packets: 37918 tx bytes: 64760298 tx packets: 42239 tx retries: 0 tx failed: 0 signal: -43 dBm signal avg: -42 dBm tx bitrate: 1053.0 MBit/s VHT-MCS 6 160MHz VHT-NSS 2 rx bitrate: 1560.0 MBit/s VHT-MCS 8 160MHz short GI VHT-NSS 2 authorized: yes authenticated: yes preamble: long WMM/WME: yes MFP: no TDLS peer: no connected time: 156 seconds Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com