Re: [PATCH] iio: pulse: Support PWM capture with TI AM3358 eCAP module

[Darren Schachter <dts86@cornell.edu>]

On Tue, Aug 18, 2020 at 4:49 PM kernel test robot <lkp@intel.com> wrote:
>
> Hi Darren,
>
> Thank you for the patch! Perhaps something to improve:
>
> [auto build test WARNING on iio/togreg]
> [also build test WARNING on linux/master linus/master v5.9-rc1 next-20200818]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
>
> url:    https://github.com/0day-ci/linux/commits/Darren-Schachter/iio-pulse-Support-PWM-capture-with-TI-AM3358-eCAP-module/20200818-233934
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
> config: nios2-allyesconfig (attached as .config)
> compiler: nios2-linux-gcc (GCC) 9.3.0
> 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
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=nios2
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
>    drivers/iio/pulse/pulse_tiecap.c: In function 'ecap_attr_prescalar_store':
> >> drivers/iio/pulse/pulse_tiecap.c:193:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
>      193 |  int ret;
>          |      ^~~
>
> # https://github.com/0day-ci/linux/commit/b454a1487cd33fe1b8962f9e6b5b0ca35b373ece
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Darren-Schachter/iio-pulse-Support-PWM-capture-with-TI-AM3358-eCAP-module/20200818-233934
> git checkout b454a1487cd33fe1b8962f9e6b5b0ca35b373ece
> vim +/ret +193 drivers/iio/pulse/pulse_tiecap.c
>
>    187
>    188  static ssize_t ecap_attr_prescalar_store(struct device *dev,
>    189                                          struct device_attribute *attr,
>    190                                          const char *buf,
>    191                                          size_t len)
>    192  {
>  > 193          int ret;
>    194          long val;
>    195          struct ecap_state *state = dev_to_ecap_state(dev);
>    196
>    197          if (test_bit(ECAP_ENABLED, &state->flags))
>    198                  return -EINVAL;
>    199
>    200          ret = kstrtol(buf, 16, &val);
>    201          if (val > 0x05 && val != 0x1E && val != 0x1F)
>    202                  return -EINVAL;
>    203
>    204          mutex_lock(&state->lock);
>    205          state->flags &= ~(0x1F << ECAP_PRESCALAR_OFFSET); // clear bits
>    206          state->flags |= (val << ECAP_PRESCALAR_OFFSET);
>    207          mutex_unlock(&state->lock);
>    208
>    209          return len;
>    210  }
>    211
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

I've made modifications to remedy this issue for version 2 of the
patch. I will wait for additional feedback before submitting version
2. I do not believe this minor change warrants a new version on its
own, but please let me know if you feel differently.