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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 F1F06C282C4 for ; Sat, 9 Feb 2019 15:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C998B217D8 for ; Sat, 9 Feb 2019 15:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726933AbfBIPzo (ORCPT ); Sat, 9 Feb 2019 10:55:44 -0500 Received: from fudo.makrotopia.org ([185.142.180.71]:46154 "EHLO fudo.makrotopia.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726907AbfBIPzo (ORCPT ); Sat, 9 Feb 2019 10:55:44 -0500 X-Greylist: delayed 989 seconds by postgrey-1.27 at vger.kernel.org; Sat, 09 Feb 2019 10:55:43 EST Received: from local by fudo.makrotopia.org with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1gsUig-0001Ao-TX; Sat, 09 Feb 2019 16:39:08 +0100 Date: Sat, 9 Feb 2019 16:38:53 +0100 From: Daniel Golle To: Tom Psyborg Cc: Stanislaw Gruszka , linux-wireless@vger.kernel.org, Randy Oostdyk , Felix Fietkau , Mathias Kresin Subject: Re: [PATCH v2 3/3] rt2x00: do not print error when queue is full Message-ID: <20190209153850.GA19297@makrotopia.org> References: <20181221095938.GA29536@redhat.com> <20181227102535.GA25885@redhat.com> <20190102081934.GA5300@redhat.com> <20190209110259.GA14900@redhat.com> <20190209115628.GA16082@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Hi Tom, On Sat, Feb 09, 2019 at 01:28:32PM +0100, Tom Psyborg wrote: > On 09/02/2019, Stanislaw Gruszka wrote: > > On Sat, Feb 09, 2019 at 12:11:03PM +0100, Tom Psyborg wrote: > >> Can you reproduce interface freeze with this patch if you enable debug > >> options to print all dbg messages? > > > > Haven't tried that, but I expect enabling debug messages will > > cause troubles at hardware where printk make CPU hog. > > > > Stanislaw > > > > Take a look at my comment from 23.01.2019. on this link: > https://bugs.openwrt.org/index.php?do=details&task_id=2018 > There might be a chance dbg printks do not cause problems. This is very likely just overheat because of missing TSSI. It happends on boards where MT7620A is used without heatsink (and easy to reproduce, I've tried. We just need TSSI and for bad board design it will mean limiting to one TX-queue soon after serious traffic starts). We should tell those users to glue heatsink on the chip for $0.05 they can fix this in hardware -- and implement TSSI to mitigate at least the very worst effects (such as hardware stuck until reset). So dkg printks can make this worse, of course, because logging overhead also burns CPU cycles and increases system load. I remember in Rt5350 (and other predecessors of Rt6352 aka. MT7620) also had problems like that and it was possible to improve it by all sorts of things like removing power from unused ports of the Ethernet switch -- so for those boards (like Xiaomi MiWiFi mini) even this maybe the trick, because they also only use 3 out of 5 ports, and maybe we need to try harder to disable the power of unused ports (and also those without cable plugged in only periodicly power them up and check for link).... Cheers Daniel