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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,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 307B1C4741F for ; Thu, 5 Nov 2020 07:40:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFBDB21741 for ; Thu, 5 Nov 2020 07:40:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604562001; bh=KHkNTPt3cIDP3t9rw9Ae0dWGwVDsCuhvWQGhvETGUKg=; h=Subject:To:Cc:References:From:Date:In-Reply-To:List-ID:From; b=MZ+kP57Dh2TdwN3z4l8dHgS32RgT0wY9N2ocTgzUsaZP+ES+H7uhUJLm3mrZE72ND waEKHDHhKLkxW9OXQ1zsA/Yq1ZAG4QYi1zE4KqujBr0dIC6IXKg/WfJaMbX2h9IB9S klDQjPfjW1H+GRaqi9gyHc1/nEX5lB0I37V+wa7o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728741AbgKEHkB (ORCPT ); Thu, 5 Nov 2020 02:40:01 -0500 Received: from mail-ej1-f65.google.com ([209.85.218.65]:38364 "EHLO mail-ej1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725320AbgKEHkA (ORCPT ); Thu, 5 Nov 2020 02:40:00 -0500 Received: by mail-ej1-f65.google.com with SMTP id za3so1195216ejb.5; Wed, 04 Nov 2020 23:39:59 -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=/PoaxSQdQ0qc6MtVRWROcDbBKMBfI1ym4uPU4Lv069A=; b=Q8khOIeRSL5Po8/WTjKtcVgVmzqqH6erORbHN5YaN+dCWQdF7oKR8NhU3lMDmN/ydb 3/uiH/SLOoZGK0LGmJci8tdRG7sconoo7laLeRA46Q9U0+LxXhu+S/SGCDzPbz7EkmQe UBSrH4cTnEtqVlAUQ0eBwQvwsWNAfYv67H0cVbNTFD+zbe8hMe+hlpYSebmvH6EoQTDN 6//xr/HHtTccJJYgfdvXfxmNCZidH7OunD+TSgh4nMGqoX5oTVJdSh/sku1JveAImJS6 wsvD7324LUvsb3KiugYn5ezWiYreXz1DGvQ7jvhqaRNCO+/vw/vAHviDoprpp1uPVDd6 7ulw== X-Gm-Message-State: AOAM533cVVTxGd3r4nKKweHYSsaUi+owwzxZ1VgEjXgu0FGAbc9CB/Wu p5YIbRk9Xh83UHg8S5MRzNZtPgBVqQc= X-Google-Smtp-Source: ABdhPJwEt20G0n1D11J5pSfi2tvzsZnG0AfTtqEF0ANZdbe1XXAbrjEon+3CwZuTF7sgXsf/suDDWQ== X-Received: by 2002:a17:906:7844:: with SMTP id p4mr1076205ejm.26.1604561998177; Wed, 04 Nov 2020 23:39:58 -0800 (PST) Received: from ?IPv6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id s3sm422116ejv.97.2020.11.04.23.39.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Nov 2020 23:39:57 -0800 (PST) Subject: Re: [PATCH 34/36] tty: serial: pmac_zilog: Make disposable variable __always_unused To: Christophe Leroy , Lee Jones Cc: Greg Kroah-Hartman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Paul Mackerras , linux-serial@vger.kernel.org References: <20201104193549.4026187-1-lee.jones@linaro.org> <20201104193549.4026187-35-lee.jones@linaro.org> <445a6440-b4c8-4536-891b-0cefc78e5f57@csgroup.eu> From: Jiri Slaby Message-ID: Date: Thu, 5 Nov 2020 08:39:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.3 MIME-Version: 1.0 In-Reply-To: <445a6440-b4c8-4536-891b-0cefc78e5f57@csgroup.eu> 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 05. 11. 20, 8:04, Christophe Leroy wrote: > > > Le 04/11/2020 à 20:35, Lee Jones a écrit : >> Fixes the following W=1 kernel build warning(s): >> >>   drivers/tty/serial/pmac_zilog.h:365:58: warning: variable ‘garbage’ >> set but not used [-Wunused-but-set-variable] > > Explain how you are fixing this warning. > > Setting  __always_unused is usually not the good solution for fixing > this warning, but here I guess this is likely the good solution. But it > should be explained why. Or, why is the "garbage =" needed in the first place? read_zsdata is not defined with __warn_unused_result__. And even if it was, would (void)!read_zsdata(port) fix it? >> Cc: Greg Kroah-Hartman >> Cc: Jiri Slaby >> Cc: Michael Ellerman >> Cc: Benjamin Herrenschmidt >> Cc: Paul Mackerras >> Cc: linux-serial@vger.kernel.org >> Cc: linuxppc-dev@lists.ozlabs.org >> Signed-off-by: Lee Jones >> --- >>   drivers/tty/serial/pmac_zilog.h | 2 +- >>   1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/tty/serial/pmac_zilog.h >> b/drivers/tty/serial/pmac_zilog.h >> index bb874e76810e0..968aec7c1cf82 100644 >> --- a/drivers/tty/serial/pmac_zilog.h >> +++ b/drivers/tty/serial/pmac_zilog.h >> @@ -362,7 +362,7 @@ static inline void zssync(struct uart_pmac_port >> *port) >>   /* Misc macros */ >>   #define ZS_CLEARERR(port)    (write_zsreg(port, 0, ERR_RES)) >> -#define ZS_CLEARFIFO(port)   do { volatile unsigned char garbage; \ >> +#define ZS_CLEARFIFO(port)   do { volatile unsigned char >> __always_unused garbage; \ >>                        garbage = read_zsdata(port); \ >>                        garbage = read_zsdata(port); \ >>                        garbage = read_zsdata(port); \ >> thanks, -- js