Re: drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match'

[Sergio Paracuellos]

Hi!

On Mon, Jul 24, 2023 at 5:21 PM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   6eaae198076080886b9e7d57f4ae06fa782f90ef
> commit: 6f3b15586eef736831abe6a14f2a6906bc0dc074 clk: ralink: add clock and reset driver for MTMIPS SoCs
> date:   5 weeks ago
> config: x86_64-buildonly-randconfig-r003-20230723 (https://download.01.org/0day-ci/archive/20230724/202307242310.CdOnd2py-lkp@xxxxxxxxx/config)
> compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
> reproduce: (https://download.01.org/0day-ci/archive/20230724/202307242310.CdOnd2py-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@xxxxxxxxx/
>
> All warnings (new ones prefixed by >>):
>
>    drivers/clk/ralink/clk-mtmips.c:309:9: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
>            return ret;
>                   ^~~
>    drivers/clk/ralink/clk-mtmips.c:285:9: note: initialize the variable 'ret' to silence this warning
>            int ret, i;
>                   ^
>                    = 0
>    drivers/clk/ralink/clk-mtmips.c:359:9: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
>            return ret;
>                   ^~~
>    drivers/clk/ralink/clk-mtmips.c:335:9: note: initialize the variable 'ret' to silence this warning
>            int ret, i;
>                   ^
>                    = 0

This two errors were already fixed in:

6e68dae946e3: ("clk: ralink: mtmips: Fix uninitialized use of ret in
mtmips_register_{fixed,factor}_clocks()")

> >> drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable]
>    static const struct of_device_id mtmips_of_match[] = {
>                                     ^
>    3 warnings generated.

This one is because CONFIG_OF is disabled so 'of_match_node()' turns
into a dummy macro. What would be the correct approach here?
Add select OF in Kconfig for this driver or silence the warning
declaring 'mtmips_of_match' with __maybe_unused?

Thanks in advance for clarification.

Best regards,
    Sergio Paracuellos

>
>
> vim +/mtmips_of_match +821 drivers/clk/ralink/clk-mtmips.c
>
>    820
>  > 821  static const struct of_device_id mtmips_of_match[] = {
>    822          {
>    823                  .compatible = "ralink,rt2880-sysc",
>    824                  .data = &rt2880_clk_data,
>    825          },
>    826          {
>    827                  .compatible = "ralink,rt3050-sysc",
>    828                  .data = &rt305x_clk_data,
>    829          },
>    830          {
>    831                  .compatible = "ralink,rt3052-sysc",
>    832                  .data = &rt305x_clk_data,
>    833          },
>    834          {
>    835                  .compatible = "ralink,rt3352-sysc",
>    836                  .data = &rt3352_clk_data,
>    837          },
>    838          {
>    839                  .compatible = "ralink,rt3883-sysc",
>    840                  .data = &rt3883_clk_data,
>    841          },
>    842          {
>    843                  .compatible = "ralink,rt5350-sysc",
>    844                  .data = &rt5350_clk_data,
>    845          },
>    846          {
>    847                  .compatible = "ralink,mt7620-sysc",
>    848                  .data = &mt7620_clk_data,
>    849          },
>    850          {
>    851                  .compatible = "ralink,mt7628-sysc",
>    852                  .data = &mt76x8_clk_data,
>    853          },
>    854          {
>    855                  .compatible = "ralink,mt7688-sysc",
>    856                  .data = &mt76x8_clk_data,
>    857          },
>    858          {}
>    859  };
>    860
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki