[PATCH] drm/mediatek/dp: Add the HDCP feature for DisplayPort

[kernel test robot]

Hi mac.shen,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linus/master v6.7-rc2]
[cannot apply to pza/reset/next pza/imx-drm/next]
[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/mac-shen/drm-mediatek-dp-Add-the-HDCP-feature-for-DisplayPort/20231125-152640
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20231124085346.26602-1-mac.shen%40mediatek.com
patch subject: [PATCH] drm/mediatek/dp: Add the HDCP feature for DisplayPort
config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20231125/202311252324.TTPd9IXz-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231125/202311252324.TTPd9IXz-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 at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311252324.TTPd9IXz-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/mediatek/mtk_dp.c:349:5: warning: no previous prototype for function 'mtk_dp_read' [-Wmissing-prototypes]
     349 | u32 mtk_dp_read(struct mtk_dp *mtk_dp, u32 offset)
         |     ^
   drivers/gpu/drm/mediatek/mtk_dp.c:349:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     349 | u32 mtk_dp_read(struct mtk_dp *mtk_dp, u32 offset)
         | ^
         | static 
>> drivers/gpu/drm/mediatek/mtk_dp.c:376:5: warning: no previous prototype for function 'mtk_dp_update_bits' [-Wmissing-prototypes]
     376 | int mtk_dp_update_bits(struct mtk_dp *mtk_dp, u32 offset,
         |     ^
   drivers/gpu/drm/mediatek/mtk_dp.c:376:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     376 | int mtk_dp_update_bits(struct mtk_dp *mtk_dp, u32 offset,
         | ^
         | static 
>> drivers/gpu/drm/mediatek/mtk_dp.c:2663:6: warning: no previous prototype for function 'mtk_dp_check_hdcp_version' [-Wmissing-prototypes]
    2663 | void mtk_dp_check_hdcp_version(struct mtk_dp *mtk_dp, bool only_hdcp1x)
         |      ^
   drivers/gpu/drm/mediatek/mtk_dp.c:2663:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
    2663 | void mtk_dp_check_hdcp_version(struct mtk_dp *mtk_dp, bool only_hdcp1x)
         | ^
         | static 
   3 warnings generated.


vim +/mtk_dp_read +349 drivers/gpu/drm/mediatek/mtk_dp.c

   348	
 > 349	u32 mtk_dp_read(struct mtk_dp *mtk_dp, u32 offset)
   350	{
   351		return mtk_dp_reg_read(mtk_dp->regs, offset);
   352	}
   353	
   354	static int mtk_dp_write(struct mtk_dp *mtk_dp, u32 offset, u32 val)
   355	{
   356		int ret = regmap_write(mtk_dp->regs, offset, val);
   357	
   358		if (ret)
   359			dev_err(mtk_dp->dev,
   360				"Failed to write register 0x%x with value 0x%x\n",
   361				offset, val);
   362		return ret;
   363	}
   364	
   365	int mtk_dp_reg_update_bits(struct regmap *regs, u32 offset,
   366				   u32 val, u32 mask)
   367	{
   368		int ret = regmap_update_bits(regs, offset, mask, val);
   369	
   370		if (ret)
   371			pr_err("Failed to update register 0x%x with value 0x%x, mask 0x%x\n",
   372			       offset, val, mask);
   373		return ret;
   374	}
   375	
 > 376	int mtk_dp_update_bits(struct mtk_dp *mtk_dp, u32 offset,
   377			       u32 val, u32 mask)
   378	{
   379		return mtk_dp_reg_update_bits(mtk_dp->regs, offset, val, mask);
   380	}
   381	

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