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 CA9A4C6FA90 for ; Thu, 22 Sep 2022 16:29:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231936AbiIVQ3T (ORCPT ); Thu, 22 Sep 2022 12:29:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229825AbiIVQ3R (ORCPT ); Thu, 22 Sep 2022 12:29:17 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AEA4E6A03 for ; Thu, 22 Sep 2022 09:29:14 -0700 (PDT) Received: from fraeml734-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4MYLG02zHlz67VyR; Fri, 23 Sep 2022 00:24:24 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (7.191.163.240) by fraeml734-chm.china.huawei.com (10.206.15.215) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 22 Sep 2022 18:29:11 +0200 Received: from localhost (10.81.208.231) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 22 Sep 2022 17:29:11 +0100 Date: Thu, 22 Sep 2022 17:29:09 +0100 From: Jonathan Cameron To: Marcus Folkesson CC: kernel test robot , , , , Andy Shevchenko , Subject: Re: [jic23-iio:testing 58/58] drivers/iio/adc/mcp3911.c:274:6: warning: variable 'tmp0' set but not used Message-ID: <20220922172909.00005beb@huawei.com> In-Reply-To: References: <202209220845.GmS9zryR-lkp@intel.com> <20220922115925.00004ec9@huawei.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.81.208.231] X-ClientProxiedBy: lhrpeml500005.china.huawei.com (7.191.163.240) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 22 Sep 2022 17:41:25 +0200 Marcus Folkesson wrote: > On Thu, Sep 22, 2022 at 11:59:25AM +0100, Jonathan Cameron wrote: > > On Thu, 22 Sep 2022 08:50:17 +0800 > > kernel test robot wrote: > > > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git testing > > > head: d4e1a549566b9ea8b96e80f0cdcbe99714ac256e > > > commit: d4e1a549566b9ea8b96e80f0cdcbe99714ac256e [58/58] iio: adc: mcp3911: add support to set PGA > > > config: x86_64-randconfig-a012 > > > compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) > > > reproduce (this is a W=1 build): > > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > > > chmod +x ~/bin/make.cross > > > # https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=d4e1a549566b9ea8b96e80f0cdcbe99714ac256e > > > git remote add jic23-iio https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git > > > git fetch --no-tags jic23-iio testing > > > git checkout d4e1a549566b9ea8b96e80f0cdcbe99714ac256e > > > # save the config file > > > mkdir build_dir && cp config build_dir/.config > > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/iio/adc/ > > > > > > If you fix the issue, kindly add following tag where applicable > > > | Reported-by: kernel test robot > > > > > > All warnings (new ones prefixed by >>): > > > > > > >> drivers/iio/adc/mcp3911.c:274:6: warning: variable 'tmp0' set but not used [-Wunused-but-set-variable] > > > int tmp0, tmp1; > > > ^ > > > 1 warning generated. > > > > > > > > > vim +/tmp0 +274 drivers/iio/adc/mcp3911.c > > > > > > 268 > > > 269 static int mcp3911_calc_scale_table(struct mcp3911 *adc) > > > 270 { > > > 271 u32 ref = MCP3911_INT_VREF_MV; > > > 272 u32 div; > > > 273 int ret; > > > > 274 int tmp0, tmp1; > > > 275 s64 tmp2; > > > 276 > > > 277 if (adc->vref) { > > > 278 ret = regulator_get_voltage(adc->vref); > > > 279 if (ret < 0) { > > > 280 dev_err(&adc->spi->dev, > > > 281 "failed to get vref voltage: %d\n", > > > 282 ret); > > > 283 return ret; > > > 284 } > > > 285 > > > 286 ref = ret / 1000; > > > 287 } > > > 288 > > > 289 /* > > > 290 * For 24-bit Conversion > > > 291 * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5 > > > 292 * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5) > > > 293 * > > > 294 * ref = Reference voltage > > > 295 * div = (2^23 * 1.5 * gain) = 12582912 * gain > > > 296 */ > > > 297 for (int i = 0; i < MCP3911_NUM_SCALES; i++) { > > > 298 div = 12582912 * BIT(i); > > > 299 tmp2 = div_s64((s64)ref * 1000000000LL, div); > > > 300 tmp1 = div; > > > 301 tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1); > > > > Marcus, > > I'm guessing the intent here is just to get the remainder. > > Hence fix is probably just to drop tmp0? > > > > If you confirm that I'll tweak the commit to do that. > > > > Jonathan > > > Hum, Yes. I actually think we can drop div, tmp0, tmp1 and tmp2. > I think they are remnats for when I did the calculation differently. > > Do you want me to update the patchset? No I'll roll this in a few minutes. > > static int mcp3911_calc_scale_table(struct mcp3911 *adc) > { > u32 ref = MCP3911_INT_VREF_MV; > - u32 div; > int ret; > - int tmp0, tmp1; > - s64 tmp2; > > > .... > > > > for (int i = 0; i < MCP3911_NUM_SCALES; i++) { > - div = 12582912 * BIT(i); > - tmp2 = div_s64((s64)ref * 1000000000LL, div); > - tmp1 = div; > - tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1); > - > mcp3911_scale_table[i][0] = 0; > - mcp3911_scale_table[i][1] = tmp1; > + mcp3911_scale_table[i][1] = 12582912 * BIT(i); > } > > > /Marcus > > > > > > > > 302 > > > 303 mcp3911_scale_table[i][0] = 0; > > > 304 mcp3911_scale_table[i][1] = tmp1; > > > 305 } > > > 306 > > > 307 return 0; > > > 308 } > > > 309 > > > > > >