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_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 9F80EC352AA for ; Tue, 1 Oct 2019 15:26:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77E952168B for ; Tue, 1 Oct 2019 15:26:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389417AbfJAP0w (ORCPT ); Tue, 1 Oct 2019 11:26:52 -0400 Received: from mga07.intel.com ([134.134.136.100]:6487 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727312AbfJAP0w (ORCPT ); Tue, 1 Oct 2019 11:26:52 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Oct 2019 08:26:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,571,1559545200"; d="scan'208";a="205086228" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.157]) by fmsmga001.fm.intel.com with SMTP; 01 Oct 2019 08:26:47 -0700 Received: by lahna (sSMTP sendmail emulation); Tue, 01 Oct 2019 18:26:46 +0300 Date: Tue, 1 Oct 2019 18:26:46 +0300 From: Mika Westerberg To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, Andreas Noever , Michael Jamet , Yehezkel Bernat , Rajmohan Mani , Nicholas Johnson , Lukas Wunner , Alan Stern , Mario.Limonciello@dell.com, Anthony Wong , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 17/22] thunderbolt: Add initial support for USB4 Message-ID: <20191001152646.GC2714@lahna.fi.intel.com> References: <20191001113830.13028-1-mika.westerberg@linux.intel.com> <20191001113830.13028-18-mika.westerberg@linux.intel.com> <20191001124748.GH2954373@kroah.com> <20191001130905.GO2714@lahna.fi.intel.com> <20191001145354.GA3366714@kroah.com> <20191001150734.GA2714@lahna.fi.intel.com> <20191001151935.GA3450435@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191001151935.GA3450435@kroah.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 01, 2019 at 05:19:35PM +0200, Greg Kroah-Hartman wrote: > On Tue, Oct 01, 2019 at 06:07:34PM +0300, Mika Westerberg wrote: > > On Tue, Oct 01, 2019 at 04:53:54PM +0200, Greg Kroah-Hartman wrote: > > > On Tue, Oct 01, 2019 at 04:09:05PM +0300, Mika Westerberg wrote: > > > > On Tue, Oct 01, 2019 at 02:47:48PM +0200, Greg Kroah-Hartman wrote: > > > > > > - Thunderbolt Controller driver. This driver is required if you > > > > > > - want to hotplug Thunderbolt devices on Apple hardware or on PCs > > > > > > - with Intel Falcon Ridge or newer. > > > > > > + USB4 (Thunderbolt) driver. USB4 is the public spec based on > > > > > > + Thunderbolt 3 protocol. This driver is required if you want to > > > > > > + hotplug Thunderbolt and USB4 compliant devices on Apple > > > > > > + hardware or on PCs with Intel Falcon Ridge or newer. > > > > > > > > > > Wait, did "old" thunderbolt just get re-branded as USB4? > > > > > > > > Not but the driver started supporting USB4 as well :) > > > > > > > > USB4 is pretty much public spec of Thunderbolt 3 but with some > > > > differences in register layouts (this is because Thunderbolt uses some > > > > vendor specific capabilities which are now moved to more "standard" > > > > places). > > > > > > Ok, then we need to rename the Kconfig option as well, otherwise no one > > > will "know" that this changed, so they will not be prompted for it. > > > > > > > > Because if I have an "old" laptop that needs Thunderbolt support, how am > > > > > I going to know it is now called USB4 instead? > > > > > > > > Well the Kconfig option tries to have both names there: > > > > > > > > tristate "USB4 (Thunderbolt) support" > > > > > > > > and then > > > > > > > > USB4 (Thunderbolt) driver. USB4 is the public spec based on > > > > Thunderbolt 3 protocol. This driver is required if you want to hotplug > > > > Thunderbolt and USB4 compliant devices on Apple hardware or on PCs > > > > with Intel Falcon Ridge or newer. > > > > > > > > and the Kconfig option is still CONFIG_THUNDERBOLT. I know this is > > > > confusing but I don't have better ideas how we can advertise both. I > > > > borrowed this "format" from firewire. > > > > > > CONFIG_USB4 instead? > > > > OK, but does that break existing .configs? I mean if you have already > > CONFIG_THUNDERBOLT in your .config/defconfig does it now just get > > dropped silently? > > Yup. And then you get asked about CONFIG_USB4 I see. > > For example firewire has CONFIG_FIREWIRE even though the "standard" name > > is IEEE 1394. I was thinking maybe we can do the same for > > USB4/Thunderbolt? > > It comes down to the what do you want to do for the next 20+ years, > explain to people that "to get USB4 support, enable CONFIG_THUNDERBOLT"? That's a very good point indeed :)