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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1ED4EC352A1 for ; Wed, 7 Dec 2022 19:15:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229743AbiLGTPO (ORCPT ); Wed, 7 Dec 2022 14:15:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229480AbiLGTPL (ORCPT ); Wed, 7 Dec 2022 14:15:11 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 172D054353 for ; Wed, 7 Dec 2022 11:15:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:References:Cc:To:From:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=tK65Hbdp4E9nHAKMcSzd2uBM1BLZIMmXYUHlYGNnj1U=; b=G79WcQnoSJ6uHnKtwqcPrbNto+ V0pNO/wUq73m1AQXgXPZmKXt8SlvOdyTDj9Yiw99AyTVawtAku1dybXcvssXgDT8xqA7NnOS46sJr S3aE3dYHgVnj6ttW2v9nWtuf2A/ddgn1dvSqjVdu7lajW/QlFzEXD1sCLRM5XIsgVoiaglBU4R2Jt 2rD/I4hldJxUzhHs8P5MVl1PFv0kN2GMTI8a0+SlCzWjOFh6pG+V81Kik5yuLfG146bRcUtEFn0ge q8EBfEFJGwL/3dKw7z5qoojAS02vEJOTx7K/TvRBvY2phKvBsChVBRo37tE5pFcs1PSfSKTLxYFLc kbVDedTg==; Received: from [2601:1c2:d80:3110::a2e7] by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1p2zsq-00AZNJ-6J; Wed, 07 Dec 2022 19:15:08 +0000 Message-ID: <09f2daca-2f5c-5371-2219-b4804a70c117@infradead.org> Date: Wed, 7 Dec 2022 11:15:07 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v2] mux: remove the Kconfig question for the subsystem Content-Language: en-US From: Randy Dunlap To: Arnd Bergmann , Peter Rosin , Linus Torvalds Cc: Greg Kroah-Hartman , Andrew Morton , Linux Kernel Mailing List References: <1499156564-29458-1-git-send-email-peda@axentia.se> <053d7bf2-9bf3-a71c-5713-7cce19413c37@infradead.org> <41a5931e-3543-6a3d-ca85-2dd8ad581f2e@infradead.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/7/22 11:03, Randy Dunlap wrote: > > > On 12/7/22 10:57, Arnd Bergmann wrote: >> On Wed, Dec 7, 2022, at 18:19, Randy Dunlap wrote: >>> On 12/7/22 00:41, Arnd Bergmann wrote: >>>> For the other subsystems I mentioned, there are occasionally >>>> problems with missing 'select' that tend to be a pain to find, >>>> compared to subsystems consistently using 'depends on', which >>>> show up as link failures in randconfig builds. >>> >>> I find that various drivers mixing the use of "select" and >>> "depends on" is problematic. >> >> Agreed. Even just mixing 'select' with user-visible symbols >> is very confusing. The two sensible ways are either using >> user-visible options with 'depends on' or hidden options with >> 'select'. >> >>> However, there was no answer for the original question: >>> How does a user enable the 4 Kconfig symbols in drivers/mux/Kconfig >>> if some other random driver has not selected MULTIPLEXER? >> >> There is no need to enable any of them in this case, because >> the mux drivers are not usable by themselves. >> >>> I.e.: >>> >>> config MUX_ADG792A >>> tristate "Analog Devices ADG792A/ADG792G Multiplexers" >>> >>> config MUX_ADGS1408 >>> tristate "Analog Devices ADGS1408/ADGS1409 Multiplexers" >>> >>> config MUX_GPIO >>> tristate "GPIO-controlled Multiplexer" >>> >>> config MUX_MMIO >>> tristate "MMIO/Regmap register bitfield-controlled Multiplexer" >>> >>> OK, MUX_MMIO is selected from some other drivers, but if that is not done, >>> how can the first 3 be enabled by a user? >> >> They cannot, that is the entire point of hiding the subsystem >> when it is not used. > > OK, if you say so. That doesn't make any sense to me, but whatever, > I'll drop it. Oops. One more thing: Your statement leads me to conclude that since nothing selects those 3 mux drivers, they don't need to be in the kernel tree at all. Done. (I hope.) -- ~Randy