From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CB8CC00454 for ; Wed, 11 Dec 2019 12:58:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0ACE72077B for ; Wed, 11 Dec 2019 12:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729132AbfLKM6I (ORCPT ); Wed, 11 Dec 2019 07:58:08 -0500 Received: from s3.sipsolutions.net ([144.76.43.62]:52958 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728128AbfLKM6I (ORCPT ); Wed, 11 Dec 2019 07:58:08 -0500 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.92.3) (envelope-from ) id 1if1Z2-0042bv-Dj; Wed, 11 Dec 2019 13:58:00 +0100 Message-ID: <8f7c0c22c9732cc831686df4b93dedf37e72d219.camel@sipsolutions.net> Subject: Re: Correct radiotap header for 802.11ad From: Johannes Berg To: Krishna Chaitanya Cc: Guy Harris , "radiotap@netbsd.org" , Simon Barber , Richard Sharpe , linux-wireless , Maya Erez , wil6210@qti.qualcomm.com Date: Wed, 11 Dec 2019 13:57:58 +0100 In-Reply-To: (sfid-20191211_103932_224888_F0B0909C) References: <38F46E1D-1C4A-48DC-A906-9522006E8474@alum.mit.edu> <1606812C-649C-4C06-ABE0-AE2F4474BCD0@alum.mit.edu> <1440402013.3735.1.camel@sipsolutions.net> <55DE44EB.6080603@superduper.net> <126B842D-05EA-4510-BC9B-DB1A4AABEC12@alum.mit.edu> <1135A126-6A5A-4C84-A52D-13C0387609CC@alum.mit.edu> <1442507879.2821.9.camel@sipsolutions.net> <4cf0c2a4a2d1cd92dff4f1a791d74523e446cf01.camel@sipsolutions.net> (sfid-20191211_103932_224888_F0B0909C) Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.2 (3.34.2-1.fc31) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Wed, 2019-12-11 at 15:09 +0530, Krishna Chaitanya wrote: > > > For both the Linux userspace reporting and radiotap then, this > > completely ignores the existence of the MCSes 9.1 and 12.1-12.6, which > > cannot be captured in either format right now. Maybe the extended SC > > MCSes are just not used by equipment in the field? > > > They are used. Unfortunately, Linux-wireless doesn't have native support for DMG > wil6210 and our driver has to workaround by using HT IE's > (ieee80211_supported_band). You make it sound like that some sort of thing that Linux cannot really do better. That's far from the truth! We keep extending this (HT, VHT, HE recently) and there's no fundamental reason we couldn't do extensions for DMG. It's just that nobody who actually has a driver for Linux bothered doing so! > > In any case, to capture DMG properly I'd say we need a new radiotap > > field with at least > > * (base) MCS > > * Extended SC MCS bit > > and it should probably optionally cover the other possible fields as > > well > > * Scrambler Initialization > > * Length (?) > > * Additional PPDU bit > > * PPDU type bit > > * Training Length > > * Beam Tracking Request > > * Last RSSI > > * Turnaround > yes, we definitely need this, there are some additional fields in > 11ay, but I guess that > discussion is for another time. Somebody (@QCA I guess, I don't have any functioning driver/hardware for Linux for this) really should sit down and define the extensions to cfg80211/nl80211 to capture the data properly, and a radiotap extension. None of that is hard, I've done it for VHT before and HE recently. johannes