From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-parisc-owner@kernel.org>
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 ACB46C07E9D
	for <linux-parisc@archiver.kernel.org>; Sat, 24 Sep 2022 10:54:09 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S233477AbiIXKyI (ORCPT <rfc822;linux-parisc@archiver.kernel.org>);
        Sat, 24 Sep 2022 06:54:08 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41148 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S233342AbiIXKyI (ORCPT
        <rfc822;linux-parisc@vger.kernel.org>);
        Sat, 24 Sep 2022 06:54:08 -0400
Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38F26DDDB0
        for <linux-parisc@vger.kernel.org>; Sat, 24 Sep 2022 03:54:06 -0700 (PDT)
Received: by mail-pj1-x102c.google.com with SMTP id s90-20020a17090a2f6300b00203a685a1aaso2513142pjd.1
        for <linux-parisc@vger.kernel.org>; Sat, 24 Sep 2022 03:54:06 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=chromium.org; s=google;
        h=in-reply-to:content-disposition:mime-version:references:message-id
         :subject:cc:to:from:date:from:to:cc:subject:date;
        bh=2T/nAXofM+cBGCCzdK/WhAhFJ6YKGhgXDN2daZJ21cQ=;
        b=RrYv3vma8l+uA3BgIPpdjCQlzwFxeVsVyO30kx+88rAIAa7gpFLg4iObx7k3VcN/IC
         4qNSedKcnXVWzGuLPpldSaHpXaIZo60/f+f/+F9dY3BXCmXoq7QTzFuQdSp0OqDFgvU6
         0/6oRZNMcaC6u0wEny+s+Sf6jsJR2wfkwfeVM=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20210112;
        h=in-reply-to:content-disposition:mime-version:references:message-id
         :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date;
        bh=2T/nAXofM+cBGCCzdK/WhAhFJ6YKGhgXDN2daZJ21cQ=;
        b=SQ2Q5GtCZrvVIZrj9xYlnZpH5KriCS/AniT+4Pq9ORKHliDrNjqAh8ruDVlmAh7qGn
         +/RqXa7C5KDlwu7LNf0gSB0G8o/GTcbOwuzJYXTKj/pmp41jL6mgmCvuNwzDlbNhd7XV
         kaQV7BGn2wnb+qhmESVErnp05gIQpgPGC778pTJine+u+UMZBUevOhHTwEU5n5OA+P15
         WhmPwq5VlWo7A99OmUSwTioq6d2tcbguDX6Ha7Wvw1B4o8ZBPkNLfJHPJpfZQc9MyVpF
         F0YHqk1ZpDU2vZqbjgBv//dr2WYGt4LKxHuv5XXFa1s2OqYTjQHo9UqT3InXdrW2ymo6
         QFLw==
X-Gm-Message-State: ACrzQf3B23evis9R6q1HjsToARLvW4ycLxzempmzGOukxMKeD5kLCJrh
        8VicXgZRPPO23HeDdz66TMWK/g==
X-Google-Smtp-Source: AMsMyM71AQgkf5TJ0FexsQnrVew9TRRjvxzcx0KaOzhnhIf9ge1do5GUeDCFKOKWjtZ7mpRdlQOLyA==
X-Received: by 2002:a17:90b:4b49:b0:202:e09c:6662 with SMTP id mi9-20020a17090b4b4900b00202e09c6662mr14180414pjb.138.1664016845708;
        Sat, 24 Sep 2022 03:54:05 -0700 (PDT)
Received: from google.com ([240f:75:7537:3187:f4de:2419:efa3:8fed])
        by smtp.gmail.com with ESMTPSA id z4-20020a1709027e8400b00177e5d83d3dsm7575087pla.170.2022.09.24.03.54.01
        (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
        Sat, 24 Sep 2022 03:54:04 -0700 (PDT)
Date:   Sat, 24 Sep 2022 19:53:59 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     John Ogness <john.ogness@linutronix.de>
Cc:     Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org,
        "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
        Helge Deller <deller@gmx.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-parisc@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH printk 11/18] printk: Convert console_drivers list to
 hlist
Message-ID: <Yy7hxxJVzY6GYHkG@google.com>
References: <20220924000454.3319186-1-john.ogness@linutronix.de>
 <20220924000454.3319186-12-john.ogness@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220924000454.3319186-12-john.ogness@linutronix.de>
Precedence: bulk
List-ID: <linux-parisc.vger.kernel.org>
X-Mailing-List: linux-parisc@vger.kernel.org

On (22/09/24 02:10), John Ogness wrote:
[..]
>  static int console_unregister_locked(struct console *console)
>  {
> -	struct console *con;
>  	int res;
>  
>  	con_printk(KERN_INFO, console, "disabled\n");
> @@ -3274,32 +3287,28 @@ static int console_unregister_locked(struct console *console)
>  	if (res > 0)
>  		return 0;
>  
> -	res = -ENODEV;
>  	console_lock();
> -	if (console_drivers == console) {
> -		console_drivers=console->next;
> -		res = 0;
> -	} else {
> -		for_each_console(con) {
> -			if (con->next == console) {
> -				con->next = console->next;
> -				res = 0;
> -				break;
> -			}
> -		}
> -	}
>  
> -	if (res)
> -		goto out_disable_unlock;
> +	/* Disable it unconditionally */
> +	console->flags &= ~CON_ENABLED;
> +
> +	if (hlist_unhashed(&console->node))
> +		goto out_unlock;

Shouldn't this set `ret` to -ENODEV before goto? Otherwise it will always
return 0 (which is set by _braille_unregister_console()).

> +
> +	hlist_del_init(&console->node);
>  
>  	/*
> +	 * <HISTORICAL>
>  	 * If this isn't the last console and it has CON_CONSDEV set, we
>  	 * need to set it on the next preferred console.
> +	 * </HISTORICAL>
> +	 *
> +	 * The above makes no sense as there is no guarantee that the next
> +	 * console has any device attached. Oh well....
>  	 */

It's complicated...