[Intel-gfx] [PATCH] drm/i915/gt: Add workaround 14016712196

[kernel test robot]

Hi Tejas,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-tip/drm-tip]

url:    https://github.com/intel-lab-lkp/linux/commits/Tejas-Upadhyay/drm-i915-gt-Add-workaround-14016712196/20230512-132314
base:   git://anongit.freedesktop.org/drm/drm-tip drm-tip
patch link:    https://lore.kernel.org/r/20230512052744.778113-1-tejas.upadhyay%40intel.com
patch subject: [Intel-gfx] [PATCH] drm/i915/gt: Add workaround 14016712196
config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20230512/202305121555.i5dslJkI-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/429038a73fb0b1cbcfa5b41e17d70e48d835d347
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Tejas-Upadhyay/drm-i915-gt-Add-workaround-14016712196/20230512-132314
        git checkout 429038a73fb0b1cbcfa5b41e17d70e48d835d347
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305121555.i5dslJkI-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/i915/gt/gen8_engine_cs.c:180:5: warning: no previous prototype for 'mtl_dummy_pipe_control' [-Wmissing-prototypes]
     180 | int mtl_dummy_pipe_control(struct i915_request *rq, u32 *cs)
         |     ^~~~~~~~~~~~~~~~~~~~~~


vim +/mtl_dummy_pipe_control +180 drivers/gpu/drm/i915/gt/gen8_engine_cs.c

   179	
 > 180	int mtl_dummy_pipe_control(struct i915_request *rq, u32 *cs)
   181	{
   182		struct intel_engine_cs *engine = rq->engine;
   183	
   184		if (IS_MTL_GRAPHICS_STEP(engine->i915, M, STEP_A0, STEP_B0) ||
   185		    IS_MTL_GRAPHICS_STEP(engine->i915, P, STEP_A0, STEP_B0)) {
   186			/* dummy PIPE_CONTROL + depth flush */
   187			cs = intel_ring_begin(rq, 6);
   188			if (IS_ERR(cs))
   189				return PTR_ERR(cs);
   190			cs = gen12_emit_pipe_control(cs,
   191						     0,
   192						     PIPE_CONTROL_DEPTH_CACHE_FLUSH,
   193						     LRC_PPHWSP_SCRATCH_ADDR);
   194			intel_ring_advance(rq, cs);
   195		}
   196	
   197		return 0;
   198	}
   199	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests