drm/amdgpu: Enter low power state if CRTC active.

CRTC in DPMS state off calls for low power state entry.
Support both atomic mode setting and pre-atomic mode setting.

v2: move comment
Acked-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -1299,24 +1299,55 @@ static int amdgpu_pmops_runtime_idle(struct device *dev)
 {
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
 	struct amdgpu_device *adev = drm_dev->dev_private;
-	struct drm_crtc *crtc;
+	/* we don't want the main rpm_idle to call suspend - we want to autosuspend */
+	int ret = 1;
 
 	if (!adev->runpm) {
 		pm_runtime_forbid(dev);
 		return -EBUSY;
 	}
 
-	list_for_each_entry(crtc, &drm_dev->mode_config.crtc_list, head) {
-		if (crtc->enabled) {
-			DRM_DEBUG_DRIVER("failing to power off - crtc active\n");
-			return -EBUSY;
+	if (amdgpu_device_has_dc_support(adev)) {
+		struct drm_crtc *crtc;
+
+		drm_modeset_lock_all(drm_dev);
+
+		drm_for_each_crtc(crtc, drm_dev) {
+			if (crtc->state->active) {
+				ret = -EBUSY;
+				break;
 			}
 		}
 
+		drm_modeset_unlock_all(drm_dev);
+
+	} else {
+		struct drm_connector *list_connector;
+		struct drm_connector_list_iter iter;
+
+		mutex_lock(&drm_dev->mode_config.mutex);
+		drm_modeset_lock(&drm_dev->mode_config.connection_mutex, NULL);
+
+		drm_connector_list_iter_begin(drm_dev, &iter);
+		drm_for_each_connector_iter(list_connector, &iter) {
+			if (list_connector->dpms ==  DRM_MODE_DPMS_ON) {
+				ret = -EBUSY;
+				break;
+			}
+		}
+
+		drm_connector_list_iter_end(&iter);
+
+		drm_modeset_unlock(&drm_dev->mode_config.connection_mutex);
+		mutex_unlock(&drm_dev->mode_config.mutex);
+	}
+
+	if (ret == -EBUSY)
+		DRM_DEBUG_DRIVER("failing to power off - crtc active\n");
+
 	pm_runtime_mark_last_busy(dev);
 	pm_runtime_autosuspend(dev);
-	/* we don't want the main rpm_idle to call suspend - we want to autosuspend */
-	return 1;
+	return ret;
 }
 
 long amdgpu_drm_ioctl(struct file *filp,