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=-2.3 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 46252C433F5 for ; Wed, 5 Sep 2018 09:55:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F012B2064D for ; Wed, 5 Sep 2018 09:55:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F012B2064D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728230AbeIEOYp (ORCPT ); Wed, 5 Sep 2018 10:24:45 -0400 Received: from mga06.intel.com ([134.134.136.31]:49140 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728114AbeIEOYp (ORCPT ); Wed, 5 Sep 2018 10:24:45 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Sep 2018 02:55:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,333,1531810800"; d="scan'208";a="78123468" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.157]) by FMSMGA003.fm.intel.com with SMTP; 05 Sep 2018 02:54:52 -0700 Received: by lahna (sSMTP sendmail emulation); Wed, 05 Sep 2018 12:54:51 +0300 Date: Wed, 5 Sep 2018 12:54:51 +0300 From: Mika Westerberg To: Lukas Wunner Cc: linux-kernel@vger.kernel.org, Andreas Noever , Michael Jamet , Yehezkel Bernat Subject: Re: [PATCH 1/3] thunderbolt: Make the driver less verbose Message-ID: <20180905095451.GI2283@lahna.fi.intel.com> References: <20180903133304.70362-1-mika.westerberg@linux.intel.com> <20180903133304.70362-2-mika.westerberg@linux.intel.com> <20180905090510.fvryu6ivxagdzoyx@wunner.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180905090510.fvryu6ivxagdzoyx@wunner.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 05, 2018 at 11:05:10AM +0200, Lukas Wunner wrote: > On Mon, Sep 03, 2018 at 04:33:02PM +0300, Mika Westerberg wrote: > > Currently the driver logs quite a lot to the system message buffer even > > when doing normal operations. This information is not useful for > > ordinary users and might even annoy some. > > No, the verbose logging is done on purpose to aid us in reverse-engineering > the protocol. For example ... > > > - tb_port_info(port, " Unknown1: %#x Unknown2: %#x Unknown3: %#x\n", > > - hop->unknown1, hop->unknown2, hop->unknown3); > > ... why do you think we're logging these seemingly stupid unknown > bitfields? Because whenever someone posts dmesg output they > inadvertantly post the contents of those unknown fields and we can > then google the value of those fields on various controllers and > machines and deduce their possible meaning. And the majority of people get tons of completely useless messages filling their dmesgs? No, I don't think that's a good thing. > By muting those messages, you're taking away our reverse enginering aids > without having released the spec, which would indeed obviate the need > for them. Please don't do that. Release the spec, *then* you can > mute the messages. Not the other way round. All the possible messages are most likely logged already and available by Googling so even if we mute the driver now, you still can find those messages in the wild. Anything running on Alpine Ridge and higher does not require reverse-engineering (even on Apple systems) because those are already supported in the driver.