Re: drivers/soc/litex/litex_soc_ctrl.c:143:34: warning: unused variable 'litex_soc_ctrl_of_match'

[Stafford Horne <shorne@gmail.com>]

On Thu, Jan 07, 2021 at 04:04:47AM +0800, kernel test robot wrote:
> Hi Pawel,
> 
> FYI, the error/warning still remains.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   e71ba9452f0b5b2e8dc8aa5445198cd9214a6a62
> commit: 22447a99c97e353bde8f90c2353873f27681d57c drivers/soc/litex: add LiteX SoC Controller driver
> date:   8 weeks ago
> config: x86_64-randconfig-a001-20210107 (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 x86_64 cross compiling tool for clang build
>         # apt-get install binutils-x86-64-linux-gnu
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=22447a99c97e353bde8f90c2353873f27681d57c
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout 22447a99c97e353bde8f90c2353873f27681d57c
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 
> 
> 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/soc/litex/litex_soc_ctrl.c:143:34: warning: unused variable 'litex_soc_ctrl_of_match' [-Wunused-const-variable]
>    static const struct of_device_id litex_soc_ctrl_of_match[] = {
>                                     ^
>    1 warning generated.
> 
> 
> vim +/litex_soc_ctrl_of_match +143 drivers/soc/litex/litex_soc_ctrl.c
> 
>    142	
>  > 143	static const struct of_device_id litex_soc_ctrl_of_match[] = {
>    144		{.compatible = "litex,soc-controller"},
>    145		{},
>    146	};
>    147	
> 

I don't use clang but GCC, and I cannot reproduce this warning.

$ make drivers/soc/litex/litex_soc_ctrl.o 
  CALL    scripts/checksyscalls.sh
  CALL    scripts/atomic/check-atomics.sh
  DESCEND  objtool
  CC      drivers/soc/litex/litex_soc_ctrl.o

Also, I can see litex_soc_ctrl_of_match is used.  I am not sure what is going on
here.

-Stafford