Re: [PATCH v2 1/1] arm64: rsi: Add automatic arm-cca-guest module loading

[Gavin Shan <gshan@redhat.com>]

On 12/3/24 4:03 PM, kernel test robot wrote:
> Hi Jeremy,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on arm64/for-next/core]
> [also build test WARNING on linus/master v6.13-rc1 next-20241128]
> [cannot apply to kvmarm/next soc/for-next arm/for-next arm/fixes]
> [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#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Jeremy-Linton/arm64-rsi-Add-automatic-arm-cca-guest-module-loading/20241203-080347
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
> patch link:    https://lore.kernel.org/r/20241203000156.72451-2-jeremy.linton%40arm.com
> patch subject: [PATCH v2 1/1] arm64: rsi: Add automatic arm-cca-guest module loading
> config: arm64-randconfig-004-20241203 (https://download.01.org/0day-ci/archive/20241203/202412031348.bp5i3ws2-lkp@intel.com/config)
> compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241203/202412031348.bp5i3ws2-lkp@intel.com/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@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202412031348.bp5i3ws2-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>>> drivers/virt/coco/arm-cca-guest/arm-cca-guest.c:224:21: warning: attribute declaration must precede definition [-Wignored-attributes]
>       224 | static const struct __maybe_unused platform_device_id arm_cca_match[] = {
>           |                     ^
>     include/linux/compiler_attributes.h:356:56: note: expanded from macro '__maybe_unused'
>       356 | #define __maybe_unused                  __attribute__((__unused__))
>           |                                                        ^
>     include/linux/mod_devicetable.h:607:8: note: previous definition is here
>       607 | struct platform_device_id {
>           |        ^
>>> drivers/virt/coco/arm-cca-guest/arm-cca-guest.c:224:55: warning: unused variable 'arm_cca_match' [-Wunused-const-variable]
>       224 | static const struct __maybe_unused platform_device_id arm_cca_match[] = {
>           |                                                       ^~~~~~~~~~~~~
>     2 warnings generated.
> 
> 
> vim +224 drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
> 
>     222	
>     223	/* modalias, so userspace can autoload this module when RSI is available */
>   > 224	static const struct __maybe_unused platform_device_id arm_cca_match[] = {
>     225		{ RSI_PDEV_NAME, 0},
>     226		{ }
>     227	};
>     228	
> 

The definition may have to be something like below, to avoid the compiling warning.

static const struct platform_device_id __maybe_unused arm_cca_match[] = {
        ...
};

Thanks,
Gavin