tree: git://anongit.freedesktop.org/drm/drm-tip drm-tip head: af383973ac39069d9ffcac0287a896a107005d54 commit: e3aae683e861a987d3d7dca593aaff93ac001bcb [1117/1129] drm: convert drm_atomic_uapi.c to new debug helpers config: i386-randconfig-m021-20201115 (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; Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; smatch warnings: drivers/gpu/drm/drm_atomic_uapi.c:342 drm_atomic_set_crtc_for_connector() error: we previously assumed 'crtc' could be null (see line 326) vim +/crtc +342 drivers/gpu/drm/drm_atomic_uapi.c 72fdb40c1a4b48f Daniel Vetter 2018-09-05 305 int 72fdb40c1a4b48f Daniel Vetter 2018-09-05 306 drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state, 72fdb40c1a4b48f Daniel Vetter 2018-09-05 307 struct drm_crtc *crtc) 72fdb40c1a4b48f Daniel Vetter 2018-09-05 308 { 72fdb40c1a4b48f Daniel Vetter 2018-09-05 309 struct drm_connector *connector = conn_state->connector; 72fdb40c1a4b48f Daniel Vetter 2018-09-05 310 struct drm_crtc_state *crtc_state; 72fdb40c1a4b48f Daniel Vetter 2018-09-05 311 72fdb40c1a4b48f Daniel Vetter 2018-09-05 312 if (conn_state->crtc == crtc) 72fdb40c1a4b48f Daniel Vetter 2018-09-05 313 return 0; 72fdb40c1a4b48f Daniel Vetter 2018-09-05 314 72fdb40c1a4b48f Daniel Vetter 2018-09-05 315 if (conn_state->crtc) { 72fdb40c1a4b48f Daniel Vetter 2018-09-05 316 crtc_state = drm_atomic_get_new_crtc_state(conn_state->state, 72fdb40c1a4b48f Daniel Vetter 2018-09-05 317 conn_state->crtc); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 318 72fdb40c1a4b48f Daniel Vetter 2018-09-05 319 crtc_state->connector_mask &= 72fdb40c1a4b48f Daniel Vetter 2018-09-05 320 ~drm_connector_mask(conn_state->connector); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 321 72fdb40c1a4b48f Daniel Vetter 2018-09-05 322 drm_connector_put(conn_state->connector); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 323 conn_state->crtc = NULL; 72fdb40c1a4b48f Daniel Vetter 2018-09-05 324 } 72fdb40c1a4b48f Daniel Vetter 2018-09-05 325 72fdb40c1a4b48f Daniel Vetter 2018-09-05 @326 if (crtc) { ^^^^ If "crtc" is NULL the error message will crash 72fdb40c1a4b48f Daniel Vetter 2018-09-05 327 crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 328 if (IS_ERR(crtc_state)) 72fdb40c1a4b48f Daniel Vetter 2018-09-05 329 return PTR_ERR(crtc_state); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 330 72fdb40c1a4b48f Daniel Vetter 2018-09-05 331 crtc_state->connector_mask |= 72fdb40c1a4b48f Daniel Vetter 2018-09-05 332 drm_connector_mask(conn_state->connector); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 333 72fdb40c1a4b48f Daniel Vetter 2018-09-05 334 drm_connector_get(conn_state->connector); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 335 conn_state->crtc = crtc; 72fdb40c1a4b48f Daniel Vetter 2018-09-05 336 e3aae683e861a98 Simon Ser 2020-11-11 337 drm_dbg_atomic(crtc->dev, e3aae683e861a98 Simon Ser 2020-11-11 338 "Link [CONNECTOR:%d:%s] state %p to [CRTC:%d:%s]\n", 72fdb40c1a4b48f Daniel Vetter 2018-09-05 339 connector->base.id, connector->name, 72fdb40c1a4b48f Daniel Vetter 2018-09-05 340 conn_state, crtc->base.id, crtc->name); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 341 } else { e3aae683e861a98 Simon Ser 2020-11-11 @342 drm_dbg_atomic(crtc->dev, ^^^^^^^^^ BOOM! e3aae683e861a98 Simon Ser 2020-11-11 343 "Link [CONNECTOR:%d:%s] state %p to [NOCRTC]\n", 72fdb40c1a4b48f Daniel Vetter 2018-09-05 344 connector->base.id, connector->name, 72fdb40c1a4b48f Daniel Vetter 2018-09-05 345 conn_state); 72fdb40c1a4b48f Daniel Vetter 2018-09-05 346 } 72fdb40c1a4b48f Daniel Vetter 2018-09-05 347 72fdb40c1a4b48f Daniel Vetter 2018-09-05 348 return 0; 72fdb40c1a4b48f Daniel Vetter 2018-09-05 349 } --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org