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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 DAAECC2D0C3 for ; Tue, 31 Dec 2019 00:59:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 97A5F2077B for ; Tue, 31 Dec 2019 00:59:48 +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="SChRRsQA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727822AbfLaA7r (ORCPT ); Mon, 30 Dec 2019 19:59:47 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:57794 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727766AbfLaA7r (ORCPT ); Mon, 30 Dec 2019 19:59:47 -0500 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=aWSBqhxb0lE9SfM+h9fKMV7nyuX+MBH/ozYu/Tw/9UQ=; b=SChRRsQAz2wMeqlwHeMNImY2G FlRsfTK+1oNFu6/CMoC7myWAtiYCm5Gpg3iEv4kytwFoeb8V2+SqCWAiAp8bFKA4HcCmeVl1qoTzH 3gLiAigOsgBWWghXDEcyxHmE9jno6TPkJyOmS5ZMcWSntg4MNPIi6TOeebKaPNwCH1m/9aIqNneCS AVyMKkS2RYoWn1i/9gEOYWSSfUJ8IzhwSNyrqLsmCivn98y06sL3x7xXeiPm1cTy/T2IUTARV6V4c 4k5c7H+Sw0u8p6fM/Ok5MnWSEtVwSseSKkqWJJky22PAOh0aLPeWIjT+UjBUeKQ8ORQjtdo/XoPTK NMJBp7sCQ==; Received: from [2601:1c0:6280:3f0::34d9] by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1im5sw-0002mF-J6; Tue, 31 Dec 2019 00:59:46 +0000 Subject: Re: Why is CONFIG_VT forced on? To: Rob Landley , linux-kernel@vger.kernel.org References: <9b79fb95-f20c-f299-f568-0ffb60305f04@landley.net> From: Randy Dunlap Message-ID: Date: Mon, 30 Dec 2019 16:59:45 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/30/19 4:53 PM, Rob Landley wrote: > > > On 12/30/19 6:36 PM, Randy Dunlap wrote: >> On 12/30/19 4:30 PM, Rob Landley wrote: >>> On x86-64 menuconfig, CONFIG_VT is forced on (in drivers->char devices->virtual >>> terminal), but the help doesn't mention a "selects", and I didn't spot anything >>> obvious in "find . -name 'Kconfig*' | xargs grep -rw VT". >>> >>> Congratulations, you've reinvented "come from". I'm mostly familiar with the >>> kconfig plumbing from _before_ you made it turing complete: how do I navigate this? >>> >>> I'm guessing "stick printfs into the menuconfig binary" is the recommended next >>> step for investigating this? Or is there a trick I'm missing? >> >> I've never had to resort to that trick. >> >>> Rob >>> >> >> config VT >> bool "Virtual terminal" if EXPERT >> depends on !UML >> select INPUT >> default y >> ^^^^^^^^^^^^^^^^^^^ >> >> That's all it takes ^^^^^^^^^^^^^^^^. > > Try to switch it off. It won't let you, it's forced on by something else. The > help doesn't say what. (That select means it's forcing CONFIG_INPUT on?) > >> Does that explain it? Maybe I don't understand the problem. > > It's possible I don't either. I can disable it when when I start from > allnoconfig and then switch CONFIG_TTY on (at which point it defaults to y, but > can be disabled). # # Character devices # CONFIG_TTY=y # CONFIG_VT is not set But first you must set/enable EXPERT. See the bool prompt. -- ~Randy