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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 D2A0EC433E0 for ; Fri, 15 Jan 2021 08:21:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9364522583 for ; Fri, 15 Jan 2021 08:21:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732540AbhAOIV3 (ORCPT ); Fri, 15 Jan 2021 03:21:29 -0500 Received: from mail-ed1-f42.google.com ([209.85.208.42]:44439 "EHLO mail-ed1-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728151AbhAOIV2 (ORCPT ); Fri, 15 Jan 2021 03:21:28 -0500 Received: by mail-ed1-f42.google.com with SMTP id p22so8560207edu.11; Fri, 15 Jan 2021 00:21:12 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=bBlGeqvogN/tfxpT7qIQYHjcZ7UeRjnnIYs3P87C0W0=; b=V+EILBiccd1Z90+EC7rLU4AyaDQCjgBEiSnLSvSzkEcYxzphMrGgZ53kHVtvH3qKyk 6CqachtFUl4oikzFDObmM3vzaAXkS5pr2n2J9rp6BUa0P6wx0T4NYJW1E3iBZSQCfNob 0NHphVmY9wUGqAOZMhdRU3KJVAWMe4WKHyvdywqkYgt0M+ilDQ/3XbvmZpPWQt/HjBsw gl/qXWu0qx5FwuOiEfO87Tkx9Tjvo4WOQSQJecYRKuApTaJq6n+n3rmCwGzAOZxbtiDH HL19qugru5q75sOuyBFky8AbtpFpjaSms+gs+Pw22n0OARTZSJlbz9cuczFWgEGVv9gA SV/Q== X-Gm-Message-State: AOAM533aC6ptx4ayBCdeKBfnUGoiUpRPdIAKDgjs3tk9MI7VvmkNkmuM ER3CarzAur1Yerqtb3ULOXRzEuje0s8= X-Google-Smtp-Source: ABdhPJwPRo+BZcR8EuEdLUaLQa2/MEEQ7N5QfiNCyKXjmI9rNiQ7nzOrspllBA1Qb61UYd4mriJXZw== X-Received: by 2002:aa7:c603:: with SMTP id h3mr8806921edq.254.1610698846251; Fri, 15 Jan 2021 00:20:46 -0800 (PST) Received: from ?IPv6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id ay24sm1005068edb.79.2021.01.15.00.20.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 15 Jan 2021 00:20:45 -0800 (PST) Subject: Re: [PATCH 3/3] tty: vcc: Drop impossible to hit WARN_ON To: =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= , Greg Kroah-Hartman Cc: "David S . Miller" , linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210114175718.137483-1-u.kleine-koenig@pengutronix.de> <20210114175718.137483-4-u.kleine-koenig@pengutronix.de> From: Jiri Slaby Message-ID: <046bdfe5-5741-0ebb-6cfd-2548f9a5543e@kernel.org> Date: Fri, 15 Jan 2021 09:20:44 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210114175718.137483-4-u.kleine-koenig@pengutronix.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14. 01. 21, 18:57, Uwe Kleine-König wrote: > vcc_get() returns the port that has provided port->index. As the port that > is about to be removed isn't removed yet this trivially will find this > port. So simplify the call to not assign an identical value to the port > pointer and drop the warning that is never hit. > > Signed-off-by: Uwe Kleine-König Reviewed-by: Jiri Slaby > --- > drivers/tty/vcc.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c > index d9b0dc6deae9..e2d6205f83ce 100644 > --- a/drivers/tty/vcc.c > +++ b/drivers/tty/vcc.c > @@ -692,12 +692,9 @@ static int vcc_remove(struct vio_dev *vdev) > tty_vhangup(port->tty); > > /* Get exclusive reference to VCC, ensures that there are no other > - * clients to this port > + * clients to this port. This cannot fail. > */ > - port = vcc_get(port->index, true); > - > - if (WARN_ON(!port)) > - return -ENODEV; > + vcc_get(port->index, true); > > tty_unregister_device(vcc_tty_driver, port->index); > > -- js