On Tue, 9 Jun 2020 04:18:56 +0800 kernel test robot <lkp@xxxxxxxxx> wrote: > Hi Tomasz, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on iio/togreg] > [also build test WARNING on robh/for-next linux/master v5.7] > [if your patch is applied to the wrong git tree, please drop us a note to help > improve the system. BTW, we also suggest to use '--base' option to specify the > base tree in git format-patch, please see https://stackoverflow.com/a/37406982] > > url: https://github.com/0day-ci/linux/commits/Tomasz-Duszynski/Add-support-for-SCD30-sensor/20200608-020304 > base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg > compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@xxxxxxxxx> I'll tidy this up whilst applying assuming nothing else comes up. No comment on it's validity as a warning, but in my view it is always squashing warnings to keep the noise low for any more useful ones (as long as it's not too costly). Jonathan > > > cppcheck warnings: (new ones prefixed by >>) > > >> drivers/iio/chemical/scd30_core.c:93:31: warning: Clarify calculation precedence for '&' and '?'. [clarifyCalculation] > sign = float32 & BIT(31) ? -1 : 1, > ^ > > vim +93 drivers/iio/chemical/scd30_core.c > > 87 > 88 /* simplified float to fixed point conversion with a scaling factor of 0.01 */ > 89 static int scd30_float_to_fp(int float32) > 90 { > 91 int fraction, shift, > 92 mantissa = float32 & GENMASK(22, 0), > > 93 sign = float32 & BIT(31) ? -1 : 1, > 94 exp = (float32 & ~BIT(31)) >> 23; > 95 > 96 /* special case 0 */ > 97 if (!exp && !mantissa) > 98 return 0; > 99 > 100 exp -= 127; > 101 if (exp < 0) { > 102 exp = -exp; > 103 /* return values ranging from 1 to 99 */ > 104 return sign * ((((BIT(23) + mantissa) * 100) >> 23) >> exp); > 105 } > 106 > 107 /* return values starting at 100 */ > 108 shift = 23 - exp; > 109 float32 = BIT(exp) + (mantissa >> shift); > 110 fraction = mantissa & GENMASK(shift - 1, 0); > 111 > 112 return sign * (float32 * 100 + ((fraction * 100) >> shift)); > 113 } > 114 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
