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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 916FDECE587 for ; Tue, 1 Oct 2019 14:54:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61BA720842 for ; Tue, 1 Oct 2019 14:54:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569941642; bh=ZZ63NgRB4la/JntiVLUk4sSc2uMP4usvtqmHwu3XxTs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=NKOPUuYOyHZAE3m3C9awMEclYGphlQfTnrI3wRzjaSJCScUpOJNk3OmiiOsK9JMIK U4dTHvp7LKXU0Iw54zETqL5KaaJMtjNvyC89uIz+B6Rn6SQ0YDCXiMAiE0ZFWW8iQ/ 66Ir9FNodtwOz3fJAq4qxcQZ5sf5S94ZVFNr20PQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389013AbfJAOx6 (ORCPT ); Tue, 1 Oct 2019 10:53:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:35820 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727143AbfJAOx6 (ORCPT ); Tue, 1 Oct 2019 10:53:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 81C1220815; Tue, 1 Oct 2019 14:53:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569941637; bh=ZZ63NgRB4la/JntiVLUk4sSc2uMP4usvtqmHwu3XxTs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oiJasVlV/zy+HQBB3apaVUeS88GLzmWZf3sELqH6JOyNmq4K7MjVnegmzgtjg/VJA S4oyDx7A4/DF7rZt9NET7tydhgIkY0UlbdfKqHHL8nkFrL8izKLBWf3MKvMtpgVqcX yO2oZq61V2mJrj8OmQqiGAZE7tXg9fIaa8964USI= Date: Tue, 1 Oct 2019 16:53:54 +0200 From: Greg Kroah-Hartman To: Mika Westerberg 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: <20191001145354.GA3366714@kroah.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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191001130905.GO2714@lahna.fi.intel.com> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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? > > Shouldn't there just be a new USB4 option that only enables/builds the > > USB4 stuff if selected? Why would I want all of this additional code on > > my old system if it's not going to do anything at all? > > USB4 devices are backward compatible with Thunderbolt 3 so you should be > able to plug in USB4 device to your old Thunderbolt 3 laptop for > example. It goes the other way as well. Some things are optional but for > example USB4 hubs must support also Thunderbolt 3. > > Does that clarify? Yes, it does, looks like marketing just renamed an old functioning system into a "brand new one!" :) thanks, greg k-h