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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 BE3B2C433ED for ; Wed, 31 Mar 2021 14:42:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 98D0061009 for ; Wed, 31 Mar 2021 14:42:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236153AbhCaOmI (ORCPT ); Wed, 31 Mar 2021 10:42:08 -0400 Received: from mga01.intel.com ([192.55.52.88]:6502 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235758AbhCaOla (ORCPT ); Wed, 31 Mar 2021 10:41:30 -0400 IronPort-SDR: Fv13a6bIFG3LRY5xUYoeoeFq3FaLHJrIaHdvrBFa8S4YpIYYDCX7whjYL0niY8J279/bq/OQIv Nl80ZXoyUyeA== X-IronPort-AV: E=McAfee;i="6000,8403,9940"; a="212259213" X-IronPort-AV: E=Sophos;i="5.81,293,1610438400"; d="scan'208";a="212259213" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2021 07:41:26 -0700 IronPort-SDR: vkzzsBYmQzWnxqIFwGewwH9SSQ55VgOas4ODz/oxJGoOE9M2SSm5/UdqrUfAr/5aPV/ogqjQBr lorrFe695/ig== X-IronPort-AV: E=Sophos;i="5.81,293,1610438400"; d="scan'208";a="610536384" Received: from erikberx-mobl4.amr.corp.intel.com (HELO [10.212.230.42]) ([10.212.230.42]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2021 07:41:25 -0700 Subject: Re: [PATCH] soundwire: qcom: use signed variable for error return To: Vinod Koul , Srinivas Kandagatla Cc: Bjorn Andersson , Bard Liao , Sanyog Kale , linux-arm-msm@vger.kernel.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, kernel test robot References: <20210331072111.2945945-1-vkoul@kernel.org> From: Pierre-Louis Bossart Message-ID: <9cdef4e9-a38a-6c77-1b23-739f85384b12@linux.intel.com> Date: Wed, 31 Mar 2021 09:41:24 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210331072111.2945945-1-vkoul@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 3/31/21 2:21 AM, Vinod Koul wrote: > We get warning for using a unsigned variable being compared to less than > zero. The comparison is correct as it checks for errors from previous > call to qcom_swrm_get_alert_slave_dev_num(), so we should use a signed > variable instead. > > drivers/soundwire/qcom.c: qcom_swrm_irq_handler() warn: impossible > condition '(devnum < 0) => (0-255 < 0)' > > Reported-by: kernel test robot > Signed-off-by: Vinod Koul > --- > drivers/soundwire/qcom.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c > index b08ecb9b418c..55ed133c6704 100644 > --- a/drivers/soundwire/qcom.c > +++ b/drivers/soundwire/qcom.c > @@ -428,7 +428,7 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id) > struct qcom_swrm_ctrl *swrm = dev_id; > u32 value, intr_sts, intr_sts_masked, slave_status; > u32 i; > - u8 devnum = 0; > + s8 devnum = 0; it's not great to store negative error codes with s8. That works in this specific case because the function only returns -EINVAL. We actually have zero occurrences of s8 in the drivers/soundwire/ code. > int ret = IRQ_HANDLED; > > swrm->reg_read(swrm, SWRM_INTERRUPT_STATUS, &intr_sts); >