Re: [PATCH v8 2/2] power: supply: bq256xx: Introduce the BQ256XX charger driver

[Sebastian Reichel]

Hi Ricardo,

On Tue, Jan 05, 2021 at 11:24:18AM +0800, kernel test robot wrote:
> Hi Ricardo,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on power-supply/for-next]
> [also build test WARNING on robh/for-next v5.11-rc2 next-20210104]
> [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/Ricardo-Rivera-Matos/Introduce-the-BQ256XX-family-of-chargers/20210105-043028
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git for-next
> config: powerpc64-randconfig-r034-20210105 (attached as .config)
> compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 5c951623bc8965fa1e89660f2f5f4a2944e4981a)
> 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
>         # install powerpc64 cross compiling tool for clang build
>         # apt-get install binutils-powerpc64-linux-gnu
>         # https://github.com/0day-ci/linux/commit/82436c2c6d99c4effb187bbd09b47c4dc59a1f3d
>         git remote add linux-review https://github.com/0day-ci/linux
>         git fetch --no-tags linux-review Ricardo-Rivera-Matos/Introduce-the-BQ256XX-family-of-chargers/20210105-043028
>         git checkout 82436c2c6d99c4effb187bbd09b47c4dc59a1f3d
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/power/supply/bq256xx_charger.c:1644:29: warning: variable 'psy_cfg' is uninitialized when used here [-Wuninitialized]
>            ret = bq256xx_parse_dt(bq, psy_cfg, dev);
>                                       ^~~~~~~
>    drivers/power/supply/bq256xx_charger.c:1618:37: note: initialize the variable 'psy_cfg' to silence this warning
>            struct power_supply_config *psy_cfg;
>                                               ^
>                                                = NULL

bah, I missed this serious issue during review :(

FWIW the compiler provided wrong solution. It would result in
dereferencing a NULL pointer afterwards since you never allocate
any memory for psy_cfg. You could of course allocate memory for
it, but power_supply_config is only needed during device
registration.

Proper solution is to initialize it as variable instead of pointer,
so that it ends up on the stack. Also you should initialize it with
{} to make sure any fields not explicitly configured are 0.

> >> drivers/power/supply/bq256xx_charger.c:1720:36: warning: unused variable 'bq256xx_acpi_match' [-Wunused-const-variable]
>    static const struct acpi_device_id bq256xx_acpi_match[] = {

For this one just change

.acpi_match_table = ACPI_PTR(bq256xx_acpi_match),

into

.acpi_match_table = bq256xx_acpi_match,

>    2 warnings generated.
> 
> 
> vim +/bq256xx_acpi_match +1720 drivers/power/supply/bq256xx_charger.c
> 
>   1719	
> > 1720	static const struct acpi_device_id bq256xx_acpi_match[] = {
>   1721		{ "bq25600", BQ25600 },
>   1722		{ "bq25600d", BQ25600D },
>   1723		{ "bq25601", BQ25601 },
>   1724		{ "bq25601d", BQ25601D },
>   1725		{ "bq25611d", BQ25611D },
>   1726		{ "bq25618", BQ25618 },
>   1727		{ "bq25619", BQ25619 },
>   1728		{},
>   1729	};
>   1730	MODULE_DEVICE_TABLE(acpi, bq256xx_acpi_match);
>   1731	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Thanks,

-- Sebastian

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