From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from s3.sipsolutions.net ([144.76.63.242]:57822 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750886AbdJXFyZ (ORCPT ); Tue, 24 Oct 2017 01:54:25 -0400 Message-ID: <1508824462.2639.25.camel@sipsolutions.net> (sfid-20171024_075430_904389_E0B70748) Subject: Re: A good way to get CSI info to user-space? From: Johannes Berg To: Ben Greear , "linux-wireless@vger.kernel.org" Date: Tue, 24 Oct 2017 07:54:22 +0200 In-Reply-To: <76d6a1ad-2dc4-0542-808f-4be459c3508a@candelatech.com> References: <6f9182c4-cff9-066c-173a-00d09af7c903@candelatech.com> <1508790635.2639.24.camel@sipsolutions.net> <76d6a1ad-2dc4-0542-808f-4be459c3508a@candelatech.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2017-10-23 at 13:59 -0700, Ben Greear wrote: > > The CSI data has variable length [1] but it's fundamentally always tied > > to a specific frame and as such we've always attached it to that frame > > using a radiotap vendor namespace. > > > > You can easily implement that in a mac80211 driver since it has support > > for that via RX_FLAG_RADIOTAP_VENDOR_DATA and the associated struct > > ieee80211_vendor_radiotap that you put into the skb's head. > > > > Why should anything else be needed? > > So this would only show up in user-space in something like a pkt-capture? Sure. But since you can easily add virtual monitor interfaces at any time, that doesn't really mean anything. johannes