From patchwork Thu Feb 25 18:32:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 387533 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 A91FEC433E0 for ; Thu, 25 Feb 2021 18:35:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6790D64E6C for ; Thu, 25 Feb 2021 18:35:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232923AbhBYSfH (ORCPT ); Thu, 25 Feb 2021 13:35:07 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47412 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233671AbhBYSd3 (ORCPT ); Thu, 25 Feb 2021 13:33:29 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lFLRJ-0002oE-GG; Thu, 25 Feb 2021 18:32:41 +0000 From: Colin King To: Jakub Kicinski , Kalle Valo , "David S . Miller" , Matthias Brugger , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] mt7601u: fix always true expression Date: Thu, 25 Feb 2021 18:32:41 +0000 Message-Id: <20210225183241.1002129-1-colin.king@canonical.com> X-Mailer: git-send-email 2.30.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Colin Ian King Currently the expression ~nic_conf1 is always true because nic_conf1 is a u16 and according to 6.5.3.3 of the C standard the ~ operator promotes the u16 to an integer before flipping all the bits. Thus the top 16 bits of the integer result are all set so the expression is always true. If the intention was to flip all the bits of nic_conf1 then casting the integer result back to a u16 is a suitabel fix. Interestingly static analyzers seem to thing a bitwise ! should be used instead of ~ for this scenario, so I think the original intent of the expression may need some extra consideration. Addresses-Coverity: ("Logical vs. bitwise operator") Fixes: c869f77d6abb ("add mt7601u driver") Signed-off-by: Colin Ian King --- drivers/net/wireless/mediatek/mt7601u/eeprom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt7601u/eeprom.c b/drivers/net/wireless/mediatek/mt7601u/eeprom.c index c868582c5d22..aa3b64902cf9 100644 --- a/drivers/net/wireless/mediatek/mt7601u/eeprom.c +++ b/drivers/net/wireless/mediatek/mt7601u/eeprom.c @@ -99,7 +99,7 @@ mt7601u_has_tssi(struct mt7601u_dev *dev, u8 *eeprom) { u16 nic_conf1 = get_unaligned_le16(eeprom + MT_EE_NIC_CONF_1); - return ~nic_conf1 && (nic_conf1 & MT_EE_NIC_CONF_1_TX_ALC_EN); + return (u16)~nic_conf1 && (nic_conf1 & MT_EE_NIC_CONF_1_TX_ALC_EN); } static void