Messages in this thread | | | Date | Thu, 22 Sep 2022 17:40:31 +0100 | From | Jonathan Cameron <> | Subject | Re: [jic23-iio:testing 58/58] drivers/iio/adc/mcp3911.c:274:6: warning: variable 'tmp0' set but not used |
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On Thu, 22 Sep 2022 17:29:09 +0100 Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:
> On Thu, 22 Sep 2022 17:41:25 +0200 > Marcus Folkesson <marcus.folkesson@gmail.com> 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 <lkp@intel.com> 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 <lkp@intel.com> > > > > > > > > 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.
Actually I'll leave it to you to post a fixed version I can apply. ref isn't used either in current code and nor is the regulator voltage. That doesn't feel right...
Please send a fix asap. For now I'm dropping the PGA patch that introduces this. If you can send an update of just that patch that would be great.
Thanks,
Jonathan
> > > > > 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 > > > > > > > > > >
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