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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40406C433FE for ; Wed, 23 Feb 2022 17:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243310AbiBWROs (ORCPT ); Wed, 23 Feb 2022 12:14:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243316AbiBWROo (ORCPT ); Wed, 23 Feb 2022 12:14:44 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 134ED2617; Wed, 23 Feb 2022 09:14:16 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id gb21so1122285pjb.5; Wed, 23 Feb 2022 09:14:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=/XeAg9ADtnz9kNlifB43swg/qGRH7F+nelBZTu66s6A=; b=BkvxaqFx5rjWa3W/xXrRTyUE4l/ps88Y9WKZ4VwdVPI9Ce8ObhM7/8iIWLjXoA2bfM blUqTs9IZbV9pGeGDUJ7SGqPvgwvALQTxu4tTwlP730DNqPSJxIxTrW6qpe0uka4uoVr IUEg6B0+LiNxwynPVQnd2wgB2ZTMf3xhYpWVONl4Okc7zwVjWQre0jEVKo9Az2ZYT5nd He98PRiNGu8A3PpPOagUr1FFDeDQpf3wER2RzUEpUuaJbcdHeh7MK446EWUfwfjv2k/M qnMfEr/OJbl3Tv9pzMkFzce1YD1k20vcoH3XyQg6VKmMXA36eIekLoRRt7E83Hd+GDJY buXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=/XeAg9ADtnz9kNlifB43swg/qGRH7F+nelBZTu66s6A=; b=LTm8LHSOHbPYupctI4SS4nNODKDO77unRwq9LgYwR5oM7XoMeL9E3bK2iODp+Ja3fi Se0cDT5JP8rXB+NhB8R9za4mO6XhgWWpKJWFT9mCt3cOevFNEboGcqMekG9MR/0UG6Ii ZVUPwtbmhy3W7g6ql2Xu9LrcCjwTr7wKpZzHj9rNVh6vPvuxbxysGtuNpCG7CUC5xFzU qGELcVKnRL3NwZ+hZkFYLyp7US2xy5st3pNgrxhbcBKQDQfxqyh4YQcSPQeLSP9556eN dpkXzTpaYRnOhgt5fL/3xmDLPEApCFPHhRNFVq8cRDoAhiWtM16sidau7YJOSPY+PhDK x5Gg== X-Gm-Message-State: AOAM533DI89CPqC4DJfFiRV5sibqT6X6S+Ly+M+fiBLBXe+W60jxnRyH qj5Rpn4LyKGlZV09Ue7TROc= X-Google-Smtp-Source: ABdhPJxTWyNWjhOu9GEOq69NbXkzL19oSyJqpDCgTobOaTVk9CZBn8abk/V8AU4itOIIz+Gyy+x1QA== X-Received: by 2002:a17:902:cccc:b0:14e:e89c:c669 with SMTP id z12-20020a170902cccc00b0014ee89cc669mr774635ple.58.1645636455415; Wed, 23 Feb 2022 09:14:15 -0800 (PST) Received: from [192.168.1.3] (ip72-194-116-95.oc.oc.cox.net. [72.194.116.95]) by smtp.gmail.com with ESMTPSA id r13sm103857pgb.22.2022.02.23.09.14.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Feb 2022 09:14:14 -0800 (PST) Message-ID: <118b98a8-918a-1350-070d-7b759e247c5f@gmail.com> Date: Wed, 23 Feb 2022 09:14:10 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Subject: Re: [PATCH v2] serial: make uart_console_write->putchar()'s character an unsigned char Content-Language: en-US To: Jiri Slaby , gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Genoud , Paul Cercueil , Tobias Klauser , Russell King , Vineet Gupta , Nicolas Ferre , Alexandre Belloni , Ludovic Desroches , Florian Fainelli , bcm-kernel-feedback-list@broadcom.com, Alexander Shiyan , Baruch Siach , "Maciej W. Rozycki" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Karol Gugala , Mateusz Holenko , Vladimir Zapolskiy , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , Taichi Sugaya , Takao Orito , Liviu Dudau , Sudeep Holla , Lorenzo Pieralisi , =?UTF-8?Q?Andreas_F=c3=a4rber?= , Manivannan Sadhasivam , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Andy Gross , Bjorn Andersson , Krzysztof Kozlowski , Orson Zhai , Baolin Wang , Chunyan Zhang , Patrice Chotard , Maxime Coquelin , Alexandre Torgue , "David S. Miller" , Peter Korsgaard , Michal Simek References: <20220223113355.30860-1-jslaby@suse.cz> From: Florian Fainelli In-Reply-To: <20220223113355.30860-1-jslaby@suse.cz> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/23/2022 3:33 AM, Jiri Slaby wrote: > Currently, uart_console_write->putchar's second parameter (the > character) is of type int. It makes little sense, provided uart_console_write() > accepts the input string as "const char *s" and passes its content -- the > characters -- to putchar(). So switch the character's type to unsigned > char. > > We don't use char as that is signed on some platforms. That would cause > troubles for drivers which (implicitly) cast the char to u16 when > writing to the device. Sign extension would happen in that case and the > value written would be completely different to the provided char. DZ is > an example of such a driver -- on MIPS, it uses u16 for dz_out in > dz_console_putchar(). > > Note we do the char -> uchar conversion implicitly in > uart_console_write(). Provided we do not change size of the data type, > sign extension does not happen there, so the problem is void. > > This makes the types consistent and unified with the rest of the uart > layer, which uses unsigned char in most places already. One exception is > xmit_buf, but that is going to be converted later. > > Signed-off-by: Jiri Slaby > Acked-by: Richard Genoud [atmel_serial] > Cc: Paul Cercueil > Cc: Tobias Klauser > Cc: Russell King > Cc: Vineet Gupta > Cc: Nicolas Ferre > Cc: Alexandre Belloni > Cc: Ludovic Desroches > Cc: Florian Fainelli > Cc: bcm-kernel-feedback-list@broadcom.com > Cc: Alexander Shiyan > Cc: Baruch Siach > Cc: "Maciej W. Rozycki" > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: Albert Ou > Cc: Shawn Guo > Cc: Sascha Hauer > Cc: Pengutronix Kernel Team > Cc: Fabio Estevam > Cc: NXP Linux Team > Cc: Karol Gugala > Cc: Mateusz Holenko > Cc: Vladimir Zapolskiy > Cc: Neil Armstrong > Cc: Kevin Hilman > Cc: Jerome Brunet > Cc: Martin Blumenstingl > Cc: Taichi Sugaya > Cc: Takao Orito > Cc: Liviu Dudau > Cc: Sudeep Holla > Cc: Lorenzo Pieralisi > Cc: "Andreas Färber" > Cc: Manivannan Sadhasivam > Cc: Michael Ellerman > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Andy Gross > Cc: Bjorn Andersson > Cc: Krzysztof Kozlowski > Cc: Orson Zhai > Cc: Baolin Wang > Cc: Chunyan Zhang > Cc: Patrice Chotard > Cc: Maxime Coquelin > Cc: Alexandre Torgue > Cc: "David S. Miller" > Cc: Peter Korsgaard > Cc: Michal Simek > --- > drivers/tty/serial/bcm63xx_uart.c | 2 +- For the above: Acked-by: Florian Fainelli -- Florian