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=-2.5 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, SPF_HELO_NONE,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from localhost (localhost [127.0.0.1]) by mail.netbsd.org (Postfix) with ESMTP id AABA884D92 for ; Wed, 11 Dec 2019 13:20:59 +0000 (UTC) Received: from mail.netbsd.org ([IPv6:::1]) by localhost (mail.netbsd.org [IPv6:::1]) (amavisd-new, port 10025) with ESMTP id 063Hy0pAL8ZU for ; Wed, 11 Dec 2019 13:20:59 +0000 (UTC) Received: from mail-yw1-xc42.google.com (mail-yw1-xc42.google.com [IPv6:2607:f8b0:4864:20::c42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.netbsd.org (Postfix) with ESMTPS id C8D9284CFC for ; Wed, 11 Dec 2019 13:20:58 +0000 (UTC) Received: by mail-yw1-xc42.google.com with SMTP id t141so8895537ywc.11 for ; Wed, 11 Dec 2019 05:20:58 -0800 (PST) MIME-Version: 1.0 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> <8f7c0c22c9732cc831686df4b93dedf37e72d219.camel@sipsolutions.net> In-Reply-To: <8f7c0c22c9732cc831686df4b93dedf37e72d219.camel@sipsolutions.net> From: Krishna Chaitanya Date: Wed, 11 Dec 2019 18:50:46 +0530 Message-ID: Subject: Re: Correct radiotap header for 802.11ad Content-Type: text/plain; charset="UTF-8" Sender: radiotap-owner@radiotap.org List-Id: List-Unsubscribe: Content-Transfer-Encoding: 8bit To: Johannes Berg Cc: Guy Harris , "radiotap@netbsd.org" , Simon Barber , Richard Sharpe , linux-wireless , Maya Erez , wil6210@qti.qualcomm.com On Wed, Dec 11, 2019 at 6:28 PM Johannes Berg wrote: > > 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! Sorry, that wasn't my intent, as there is a single upstream driver I guess it was easier to workaround than to properly add support. I agree that it shouldn't be hard, may be we can do it properly for 11ay. > > > 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.