Return-path: Received: from mail-it0-f45.google.com ([209.85.214.45]:35523 "EHLO mail-it0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932114AbcFJPww (ORCPT ); Fri, 10 Jun 2016 11:52:52 -0400 Received: by mail-it0-f45.google.com with SMTP id z189so185083057itg.0 for ; Fri, 10 Jun 2016 08:52:52 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <87wplxawjx.fsf@toke.dk> References: <20160603165144.17356-1-toke@toke.dk> <20160603165144.17356-6-toke@toke.dk> <8737orucq4.fsf@toke.dk> <87k2i1ml43.fsf@toke.dk> <87wpm1b6bu.fsf@toke.dk> <87inxhl90y.fsf@toke.dk> <877fdxl8cu.fsf@toke.dk> <8737oll6fu.fsf@toke.dk> <87wplxawjx.fsf@toke.dk> From: Adrian Chadd Date: Fri, 10 Jun 2016 08:52:50 -0700 Message-ID: (sfid-20160610_175256_117420_6A06C3DE) Subject: Re: [Make-wifi-fast] [RFC/RFT 5/5] ath9k: Count RX airtime in airtime deficit To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: Michal Kazior , make-wifi-fast@lists.bufferbloat.net, ath9k-devel , "linux-wireless@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: [picking a random email to reply to] I /think/ the TSF is only valid for the last frame of an aggregate. 'more' means "this RX frame is split across multiple RX descriptors" "moreaggr" means "there's more subframes in this RX'ed A-MPDU" If you get a TSF in the first frame, it's whatever was left over at that point in the RX FIFO when it was last updated; it isn't an actual timestamp timestamp. The logic for populating the descriptor contents just takes stuff out of certain offsets in the RX FIFO, and sometimes that contains stale/wrong data. I'll go and double/triple check this (as well as where the TSF is actually stamped - I think it's actually stamped at the leading edge of a packet, but stamped at the /end/ of it.) -adrian