Hi Kuogee, Thank you for the patch! Yet something to improve: [auto build test ERROR on d1ea914925856d397b0b3241428f20b945e31434] url: https://github.com/0day-ci/linux/commits/Kuogee-Hsieh/drm-msm-dp-return-c... base: d1ea914925856d397b0b3241428f20b945e31434 config: arm-defconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/8f18f61416789c76c57982b9c730c2a69... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Kuogee-Hsieh/drm-msm-dp-return-correct-connection-status-after-suspend/20201014-073608 git checkout 8f18f61416789c76c57982b9c730c2a69518203d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/gpu/drm/msm/dp/dp_display.c: In function 'msm_dp_display_enable': 1382 | if (state == ST_DISPLAY_OFF) | ^~~~~~~~~~~~~~ drivers/gpu/drm/msm/dp/dp_display.c:1382:15: note: each undeclared identifier is reported only once for each function it appears in vim +/ST_DISPLAY_OFF +1382 drivers/gpu/drm/msm/dp/dp_display.c 1349 1350 int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder) 1351 { 1352 int rc = 0; 1353 struct dp_display_private *dp_display; 1354 u32 state; 1355 1356 dp_display = container_of(dp, struct dp_display_private, dp_display); 1357 if (!dp_display->dp_mode.drm_mode.clock) { 1358 DRM_ERROR("invalid params\n"); 1359 return -EINVAL; 1360 } 1361 1362 mutex_lock(&dp_display->event_mutex); 1363 1364 dp_del_event(dp_display, EV_CONNECT_PENDING_TIMEOUT); 1365 1366 rc = dp_display_set_mode(dp, &dp_display->dp_mode); 1367 if (rc) { 1368 DRM_ERROR("Failed to perform a mode set, rc=%d\n", rc); 1369 mutex_unlock(&dp_display->event_mutex); 1370 return rc; 1371 } 1372 1373 rc = dp_display_prepare(dp); 1374 if (rc) { 1375 DRM_ERROR("DP display prepare failed, rc=%d\n", rc); 1376 mutex_unlock(&dp_display->event_mutex); 1377 return rc; 1378 } 1379 1380 state = dp_display->hpd_state; 1381 1383 dp_display_host_init(dp_display); 1384 1385 dp_display_enable(dp_display, 0); 1386 1387 rc = dp_display_post_enable(dp); 1388 if (rc) { 1389 DRM_ERROR("DP display post enable failed, rc=%d\n", rc); 1390 dp_display_disable(dp_display, 0); 1391 dp_display_unprepare(dp); 1392 } 1393 1394 if (state == ST_SUSPEND_PENDING) 1395 dp_add_event(dp_display, EV_IRQ_HPD_INT, 0, 0); 1396 1397 /* completed connection */ 1398 dp_display->hpd_state = ST_CONNECTED; 1399 1400 mutex_unlock(&dp_display->event_mutex); 1401 1402 return rc; 1403 } 1404 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org