From patchwork Fri Dec 16 09:26:54 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Sakamoto X-Patchwork-Id: 9478885 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1C86E60237 for ; Sat, 17 Dec 2016 05:46:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0C7842840E for ; Sat, 17 Dec 2016 05:46:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 016A12843E; Sat, 17 Dec 2016 05:46:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6FFA62840E for ; Sat, 17 Dec 2016 05:46:44 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7BFDB6E1B5; Sat, 17 Dec 2016 05:46:23 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from smtp-proxy004.phy.lolipop.jp (smtp-proxy004.phy.lolipop.jp [157.7.104.45]) by gabe.freedesktop.org (Postfix) with ESMTPS id 542D96EB85 for ; Fri, 16 Dec 2016 09:26:59 +0000 (UTC) Received: from smtp-proxy004.phy.lolipop.lan (HELO smtp-proxy004.phy.lolipop.jp) (172.19.44.45) (smtp-auth username m12129643-o-takashi, mechanism plain) by smtp-proxy004.phy.lolipop.jp (qpsmtpd/0.82) with ESMTPA; Fri, 16 Dec 2016 18:26:56 +0900 Received: from 127.0.0.1 (127.0.0.1) by smtp-proxy004.phy.lolipop.jp (LOLIPOP-Fsecure); Fri, 16 Dec 2016 18:26:54 +0900 (JST) X-Virus-Status: clean(LOLIPOP-Fsecure) From: Takashi Sakamoto To: tiwai@suse.de, broonie@kernel.org, perex@perex.cz Subject: [alsa-lib][PATCH] ASoC: hdmi-codec: use unsigned type to structure members with bit-field instead of signed type Date: Fri, 16 Dec 2016 18:26:54 +0900 Message-Id: <20161216092654.7773-1-o-takashi@sakamocchi.jp> X-Mailer: git-send-email 2.9.3 X-Mailman-Approved-At: Sat, 17 Dec 2016 05:46:01 +0000 Cc: alsa-devel@alsa-project.org, Jie Qiu , Arnaud Pouliquen , dri-devel@lists.freedesktop.org, Srinivas Kandagatla , Jyri Sarha , stable@vger.kernel.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP This is a fix for Linux 4.10-rc1. In C language specification, a bit-field is interpreted as a signed or unsigned integer type consisting of the specified number of bits. In GCC manual, the range of a signed bit field of N bits is from -(2^N) / 2 to ((2^N) / 2) - 1 https://www.gnu.org/software/gnu-c-manual/gnu-c-manual.html#Bit-Fields Therefore, when defined as 1 bit-field with signed type, variables can represents -1 and 0. The snd-soc-hdmi-codec module includes a structure which has signed type members with bit-fields. Codes of this module assign 0 and 1 to the members. This seems to result in implementation-dependent behaviours. As of v4.10-rc1 merge window, outside of sound subsystem, this structure is referred by below GPU modules. - tda998x - sti-drm - mediatek-drm-hdmi - msm As long as I review their codes relevant to the structure, the structure members are used just for condition statements and printk formats. My proposal of change is a bit intrusive to the printk formats but this may be acceptable. Totally, it's reasonable to use unsigned type for the structure members. This bug is detected by Sparse, static code analyzer with below warnings. ./include/sound/hdmi-codec.h:39:26: error: dubious one-bit signed bitfield ./include/sound/hdmi-codec.h:40:28: error: dubious one-bit signed bitfield ./include/sound/hdmi-codec.h:41:29: error: dubious one-bit signed bitfield ./include/sound/hdmi-codec.h:42:31: error: dubious one-bit signed bitfield CC: Jyri Sarha CC: Jie Qiu CC: Arnaud Pouliquen CC: Srinivas Kandagatla CC: dri-devel@lists.freedesktop.org CC: stable@vger.kernel.org Fixes: 09184118a8ab ("ASoC: hdmi-codec: Add hdmi-codec for external HDMI-encoders") Signed-off-by: Takashi Sakamoto --- include/sound/hdmi-codec.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/sound/hdmi-codec.h b/include/sound/hdmi-codec.h index 530c57b..915c435 100644 --- a/include/sound/hdmi-codec.h +++ b/include/sound/hdmi-codec.h @@ -36,10 +36,10 @@ struct hdmi_codec_daifmt { HDMI_AC97, HDMI_SPDIF, } fmt; - int bit_clk_inv:1; - int frame_clk_inv:1; - int bit_clk_master:1; - int frame_clk_master:1; + unsigned int bit_clk_inv:1; + unsigned int frame_clk_inv:1; + unsigned int bit_clk_master:1; + unsigned int frame_clk_master:1; }; /*