Hi Tomi, I love your patch! Perhaps something to improve: [auto build test WARNING on drm-intel/for-linux-next] [also build test WARNING on linus/master v5.10-rc7] [cannot apply to drm-tip/drm-tip anholt/for-next next-20201210] [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] url: https://github.com/0day-ci/linux/commits/Tomi-Valkeinen/drm-fix-and-clean... base: git://anongit.freedesktop.org/drm-intel for-linux-next config: i386-randconfig-m021-20201209 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; New smatch warnings: drivers/gpu/drm/drm_color_mgmt.c:307 drm_crtc_legacy_gamma_set() error: potential null dereference 'blob'. (drm_property_create_blob returns null) Old smatch warnings: drivers/gpu/drm/drm_color_mgmt.c:214 drm_mode_crtc_set_gamma_size() warn: double check that we're allocating correct size: 2 vs 6 vim +/blob +307 drivers/gpu/drm/drm_color_mgmt.c 253 254 /** 255 * drm_crtc_legacy_gamma_set - set the legacy gamma correction table 256 * @crtc: CRTC object 257 * @red: red correction table 258 * @green: green correction table 259 * @blue: green correction table 260 * @size: size of the tables 261 * @ctx: lock acquire context 262 * 263 * Implements support for legacy gamma correction table for drivers 264 * that have set drm_crtc_funcs.gamma_set or that support color management 265 * through the DEGAMMA_LUT/GAMMA_LUT properties. See 266 * drm_crtc_enable_color_mgmt() and the containing chapter for 267 * how the atomic color management and gamma tables work. 268 * 269 * This function sets the gamma using the first one available: 270 * - drm_crtc_funcs.gamma_set() 271 * - GAMMA_LUT 272 * - DEGAMMA_LUT 273 */ 274 int drm_crtc_legacy_gamma_set(struct drm_crtc *crtc, 275 u16 *red, u16 *green, u16 *blue, 276 uint32_t size, 277 struct drm_modeset_acquire_ctx *ctx) 278 { 279 struct drm_device *dev = crtc->dev; 280 struct drm_atomic_state *state; 281 struct drm_crtc_state *crtc_state; 282 struct drm_property_blob *blob = NULL; 283 struct drm_color_lut *blob_data; 284 int i, ret = 0; 285 bool replaced; 286 287 if (crtc->funcs->gamma_set) 288 return crtc->funcs->gamma_set(crtc, red, green, blue, size, ctx); 289 290 if (!crtc->has_gamma_prop && !crtc->has_degamma_prop) 291 return -ENODEV; 292 293 state = drm_atomic_state_alloc(crtc->dev); 294 if (!state) 295 return -ENOMEM; 296 297 blob = drm_property_create_blob(dev, 298 sizeof(struct drm_color_lut) * size, 299 NULL); 300 if (IS_ERR(blob)) { 301 ret = PTR_ERR(blob); 302 blob = NULL; 303 goto fail; 304 } 305 306 /* Prepare GAMMA_LUT with the legacy values. */ 308 for (i = 0; i < size; i++) { 309 blob_data[i].red = red[i]; 310 blob_data[i].green = green[i]; 311 blob_data[i].blue = blue[i]; 312 } 313 314 state->acquire_ctx = ctx; 315 crtc_state = drm_atomic_get_crtc_state(state, crtc); 316 if (IS_ERR(crtc_state)) { 317 ret = PTR_ERR(crtc_state); 318 goto fail; 319 } 320 321 /* Set GAMMA/DEGAMMA_LUT and reset DEGAMMA/GAMMA_LUT and CTM */ 322 replaced = drm_property_replace_blob(&crtc_state->degamma_lut, 323 crtc->has_gamma_prop ? NULL : blob); 324 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL); 325 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, 326 crtc->has_gamma_prop ? blob : NULL); 327 crtc_state->color_mgmt_changed |= replaced; 328 329 ret = drm_atomic_commit(state); 330 331 fail: 332 drm_atomic_state_put(state); 333 drm_property_blob_put(blob); 334 return ret; 335 } 336 EXPORT_SYMBOL(drm_crtc_legacy_gamma_set); 337 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org