[PATCH V11 28/47] drm/amd/display: Add support for sRGB EOTF in BLND block

[kernel test robot]

Hi Alex,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-exynos/exynos-drm-next]
[also build test WARNING on linus/master v6.17-rc1 next-20250815]
[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/Alex-Hung/drm-Add-helper-for-conversion-from-signed-magnitude/20250815-120435
base:   https://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos.git exynos-drm-next
patch link:    https://lore.kernel.org/r/20250815035047.3319284-29-alex.hung%40amd.com
patch subject: [PATCH V11 28/47] drm/amd/display: Add support for sRGB EOTF in BLND block
config: arm64-randconfig-002-20250816 (https://download.01.org/0day-ci/archive/20250816/202508161043.tvyKbLyZ-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 93d24b6b7b148c47a2fa228a4ef31524fa1d9f3f)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250816/202508161043.tvyKbLyZ-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/202508161043.tvyKbLyZ-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_color.c:1295:35: warning: variable 'blend_lut' is uninitialized when used here [-Wuninitialized]
    1295 |                 return __set_input_tf(NULL, tf, blend_lut, blend_size);
         |                                                 ^~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_color.c:1276:39: note: initialize the variable 'blend_lut' to silence this warning
    1276 |         const struct drm_color_lut *blend_lut;
         |                                              ^
         |                                               = NULL
   1 warning generated.


vim +/blend_lut +1295 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_color.c

  1272	
  1273		struct dc_transfer_func *tf = &dc_plane_state->blend_tf;
  1274		struct drm_colorop *colorop = colorop_state->colorop;
  1275		struct drm_device *drm = colorop->dev;
  1276		const struct drm_color_lut *blend_lut;
  1277		uint32_t blend_size = 0;
  1278	
  1279		if (colorop->type != DRM_COLOROP_1D_CURVE &&
  1280		    colorop_state->curve_1d_type != DRM_COLOROP_1D_CURVE_SRGB_EOTF)
  1281			return -EINVAL;
  1282	
  1283		if (colorop_state->bypass) {
  1284			tf->type = TF_TYPE_BYPASS;
  1285			tf->tf = TRANSFER_FUNCTION_LINEAR;
  1286			return 0;
  1287		}
  1288	
  1289		drm_dbg(drm, "Blend colorop with ID: %d\n", colorop->base.id);
  1290	
  1291		if (colorop->type == DRM_COLOROP_1D_CURVE) {
  1292			tf->type = TF_TYPE_DISTRIBUTED_POINTS;
  1293			tf->tf = amdgpu_colorop_tf_to_dc_tf(colorop_state->curve_1d_type);
  1294			tf->sdr_ref_white_level = SDR_WHITE_LEVEL_INIT_VALUE;
> 1295			return __set_input_tf(NULL, tf, blend_lut, blend_size);
  1296		}
  1297	
  1298		return -EINVAL;
  1299	}
  1300	

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