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-14016712196/20230531-222808 base: git://anongit.freedesktop.org/drm/drm-tip drm-tip patch link: https://lore.kernel.org/r/20230531143214.1650701-1-tejas.upadhyay%40intel.com patch subject: [PATCH V3] drm/i915/gt: Add workaround 14016712196 config: x86_64-randconfig-x052-20230531 (https://download.01.org/0day-ci/archive/20230601/202306010101.NktWIqo7-lkp@xxxxxxxxx/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce (this is a W=1 build): mkdir -p ~/bin wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/1ef791c16c322ffff65d4f14a0f4c09434d91884 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-14016712196/20230531-222808 git checkout 1ef791c16c322ffff65d4f14a0f4c09434d91884 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross 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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202306010101.NktWIqo7-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> drivers/gpu/drm/i915/gt/gen8_engine_cs.c:185:6: warning: variable 'cs' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (IS_MTL_GRAPHICS_STEP(rq->engine->i915, M, STEP_A0, STEP_B0) || ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/i915/i915_drv.h:684:2: note: expanded from macro 'IS_MTL_GRAPHICS_STEP' (IS_SUBPLATFORM(__i915, INTEL_METEORLAKE, INTEL_SUBPLATFORM_##variant) && \ ^ drivers/gpu/drm/i915/gt/gen8_engine_cs.c:201:9: note: uninitialized use occurs here return cs; ^~ drivers/gpu/drm/i915/gt/gen8_engine_cs.c:185:2: note: remove the 'if' if its condition is always true if (IS_MTL_GRAPHICS_STEP(rq->engine->i915, M, STEP_A0, STEP_B0) || ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> drivers/gpu/drm/i915/gt/gen8_engine_cs.c:186:6: warning: variable 'cs' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] IS_MTL_GRAPHICS_STEP(rq->engine->i915, P, STEP_A0, STEP_B0)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/i915/i915_drv.h:684:3: note: expanded from macro 'IS_MTL_GRAPHICS_STEP' (IS_SUBPLATFORM(__i915, INTEL_METEORLAKE, INTEL_SUBPLATFORM_##variant) && \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/i915/gt/gen8_engine_cs.c:201:9: note: uninitialized use occurs here return cs; ^~ drivers/gpu/drm/i915/gt/gen8_engine_cs.c:186:6: note: remove the '&&' if its condition is always true IS_MTL_GRAPHICS_STEP(rq->engine->i915, P, STEP_A0, STEP_B0)) { ^ drivers/gpu/drm/i915/i915_drv.h:684:3: note: expanded from macro 'IS_MTL_GRAPHICS_STEP' (IS_SUBPLATFORM(__i915, INTEL_METEORLAKE, INTEL_SUBPLATFORM_##variant) && \ ^ drivers/gpu/drm/i915/gt/gen8_engine_cs.c:182:9: note: initialize the variable 'cs' to silence this warning u32 *cs; ^ = NULL 2 warnings generated. vim +185 drivers/gpu/drm/i915/gt/gen8_engine_cs.c 179 180 static u32 *mtl_dummy_pipe_control(struct i915_request *rq) 181 { 182 u32 *cs; 183 184 /* Wa_14016712196 */ > 185 if (IS_MTL_GRAPHICS_STEP(rq->engine->i915, M, STEP_A0, STEP_B0) || > 186 IS_MTL_GRAPHICS_STEP(rq->engine->i915, P, STEP_A0, STEP_B0)) { 187 int ret; 188 189 /* dummy PIPE_CONTROL + depth flush */ 190 cs = intel_ring_begin(rq, 6); 191 ret = IS_ERR(cs); 192 if (ret) 193 return ERR_PTR(ret); 194 cs = gen12_emit_pipe_control(cs, 195 0, 196 PIPE_CONTROL_DEPTH_CACHE_FLUSH, 197 LRC_PPHWSP_SCRATCH_ADDR); 198 intel_ring_advance(rq, cs); 199 } 200 > 201 return cs; 202 } 203 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki