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_PASS autolearn=ham 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 3CD2EC43382 for ; Thu, 27 Sep 2018 07:13:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E055B204EC for ; Thu, 27 Sep 2018 07:12:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E055B204EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sipsolutions.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-wireless-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726784AbeI0N3p (ORCPT ); Thu, 27 Sep 2018 09:29:45 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:51734 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726669AbeI0N3p (ORCPT ); Thu, 27 Sep 2018 09:29:45 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.91) (envelope-from ) id 1g5QTn-00069p-Rs; Thu, 27 Sep 2018 09:12:56 +0200 Message-ID: <1538032363.14416.2.camel@sipsolutions.net> Subject: Re: How many null-data probes on connection loss? From: Johannes Berg To: Ben Greear , "linux-wireless@vger.kernel.org" Date: Thu, 27 Sep 2018 09:12:43 +0200 In-Reply-To: References: <9a1447d9-9a61-dc2d-0101-33c6bdeb946f@candelatech.com> <1537951137.28767.5.camel@sipsolutions.net> <1537986415.28767.17.camel@sipsolutions.net> <7ed031b0-19d9-46db-33d9-082999e5ed22@candelatech.com> <1537987703.28767.22.camel@sipsolutions.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 (3.26.6-1.fc27) 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, 2018-09-26 at 15:21 -0700, Ben Greear wrote: > > Now only 4 retries per frame, but it seems mac80211 is all 5 of its > null-data probes within a few miliseconds. Is that expected, or should > there be a bit more pause between each of the probe requests to better > weather periodic network glitches? Hmm. That's a good point, but it seems we've never considered this before. This must be a consequence of retrying immediately on lost ACK, but I guess I could see that delaying it for a little bit would make sense. We do delay it if there's no reliable ACK reporting, IIRC, but if we know it failed for sure ... It seems though that if there's some noise or so on the channel you wouldn't be transmitting, so what kind of "network glitches" might affect this? AP going away unexpectedly for some time? johannes