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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 A736CC10F14 for ; Sun, 21 Apr 2019 15:56:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 738AB2075A for ; Sun, 21 Apr 2019 15:56:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="P4pm51qq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727599AbfDUPz7 (ORCPT ); Sun, 21 Apr 2019 11:55:59 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:60120 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727228AbfDUPz6 (ORCPT ); Sun, 21 Apr 2019 11:55:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:To: Subject:Sender:Reply-To:Cc:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=NBvhVPd8Qu3O8fth05cQIOka+zx6SaVtqkXym6E0tbk=; b=P4pm51qqZsBoHGTwnQOMRpt69 B/r8MuqRNwChKJ7koLcqfNIpUrGqaCtsZ5PpCx6nc/19Hk9Cs90SJ2m+pDCQJg8XLBgFB/N1bNIIW cpk13ozY9OXs37u3wlCqKp1+15plIW/CWAcb9KKde0a7oH849dqKl7AdQ68B7+RPyrgP5YmCBip2J XbHIFBLYCVlHu1NrMbrmmcfyfzsGPbdl9p6gtLqL2emIZU7q5CJ3EvEuZ7x6pmkVUIAzeKXzLmNSm QOGTkjkeIVvT36DKKmpic1A0GGoNn8UgDsbXTkt3B2L9s9CIe8E5EOLf4c4k9wNxQluMR+4Mzse64 00US7HOxA==; Received: from static-50-53-52-16.bvtn.or.frontiernet.net ([50.53.52.16] helo=midway.dunlab) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hIEov-0004zD-Jt; Sun, 21 Apr 2019 15:55:57 +0000 Subject: Re: Reasons for oldconfig resetting config options to =m To: =?UTF-8?Q?Niklas_Hamb=c3=bcchen?= , lkml References: <9500a6a9-d63c-4572-7281-50e744c15679@nh2.me> From: Randy Dunlap Message-ID: Date: Sun, 21 Apr 2019 08:55:56 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <9500a6a9-d63c-4572-7281-50e744c15679@nh2.me> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/21/19 8:11 AM, Niklas Hambüchen wrote: > When you set an option to `=y` but one of its dependencies is set to `=m`, then `make oldconfig` will reset it back to `=m` as well. > > That makes sense, but does there exist a feature somewhere that can tell me explicitly when this happens, ideally with a reason like: > > Resetting CONFIG_USB_STORAGE from =y to =m > because its dependency CONFIG_... is set to =m > Consequently also resetting the following dependent options from =y to =m: > CONFIG_USB_STORAGE_REALTEK > CONFIG_USB_... > > This would help tuning kernel configs in situations where menuconfig is not appropriate, for example when working with diffs of configs. > > Is there such tooling, or what do people use? When using 'make menuconfig', enter /usb_storage and it says: │ Symbol: USB_STORAGE [=m] │ │ Type : tristate │ │ Prompt: USB Mass Storage support │ │ Location: │ │ -> Device Drivers │ │ (1) -> USB support (USB_SUPPORT [=y]) │ │ Defined at drivers/usb/storage/Kconfig:9 │ │ Depends on: USB_SUPPORT [=y] && USB [=m] && SCSI [=m] so it is limited to m (or n) by USB and SCSI. Or you can just find the symbol of interest and use Help to get the same info. The same can be done with 'make nconfig'. With 'make xconfig', if you click on "USB Mass Storage support" (e.g.), it shows the same info. Or you can use Ctrl+F (or Edit/Find), enter a symbol (or a partial symbol name), like USB_STORAGE, which gives you a list of symbols. Click on one of them and it will give you the same info. HTH. There is nothing quite as explicit as your example output. -- ~Randy