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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,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 7B9C5C5519F for ; Fri, 20 Nov 2020 14:25:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05F4D2223F for ; Fri, 20 Nov 2020 14:25:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="jKRUwi/p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727793AbgKTOYk (ORCPT ); Fri, 20 Nov 2020 09:24:40 -0500 Received: from mx2.suse.de ([195.135.220.15]:40492 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727241AbgKTOYj (ORCPT ); Fri, 20 Nov 2020 09:24:39 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1605882278; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=sBNRtXPgIFrwBxBRZV+yOpZA9Rsx/wRrIx/DAGNkojI=; b=jKRUwi/pVrbuG0IzqKtCNs15kXkRGA3ebX5i3HZ8hH7rg45Brn1BjpgisDbA9mSHON0kWL MJpBS4Ghj74nrz9jSXXJU+NXJg9QJoQ13PXpn+juVJHHEzlZDqRA0xwOird+M25rDkKn5V DcwNIyiRWcIHd+yDI9jaem/TLNAp4zo= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 732B5AE93; Fri, 20 Nov 2020 14:24:38 +0000 (UTC) Date: Fri, 20 Nov 2020 15:24:37 +0100 From: Petr Mladek To: Sergey Senozhatsky , Steven Rostedt , John Ogness Cc: Linus Torvalds , Guenter Roeck , Shreyas Joshi , shreyasjoshi15@gmail.com, Greg Kroah-Hartman , Sergey Senozhatsky , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] printk/console: Use ttynull when no console is available or wanted Message-ID: References: <20201111135450.11214-1-pmladek@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201111135450.11214-1-pmladek@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 2020-11-11 14:54:48, Petr Mladek wrote: > This is another attempt to solve regression caused by the commit > 48021f98130880dd74 ("printk: handle blank console arguments passed in."). > > It prevented a crash caused by empty console= parameter. But it caused > performance problems on Chromebooks because they use it to disable > all consoles, see > see https://lore.kernel.org/r/20201006025935.GA597@jagdpanzerIV.localdomain > > Solve both problems by using ttynull console driver that was crated > exactly for this purpose. > > The 1st patch should prevent the crash for any invalid console name. > > The 2nd patch allows to used the ttynull driver also with the widely > used console= and console=null parameters. > > Best Regards, > Petr > > Petr Mladek (2): > init/console: Use ttynull as a fallback when there is no console > printk/console: Allow to disable console output by using console="" or > console=null The patchset has been committed into printk/linux.git, branch for-5.11-null-console. Best Regards, Petr