drm/amd/display: Fix memleaks when atomic check fails.

While checking plane states for updates during atomic check, we create
dc_plane_states in preparation. These dc states should be freed if
something errors.

Although the input transfer function is also freed by
dc_plane_state_release(), we should free it (on error) under the same
scope as where it is created.
Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -4707,6 +4707,7 @@ static int dm_update_planes_state(struct dc *dc,
 			*lock_and_validation_needed = true;
 
 		} else { /* Add new planes */
+			struct dc_plane_state *dc_new_plane_state;
 
 			if (drm_atomic_plane_disabling(plane->state, new_plane_state))
 				continue;
@@ -4725,35 +4726,45 @@ static int dm_update_planes_state(struct dc *dc,
 
 			WARN_ON(dm_new_plane_state->dc_state);
 
-			dm_new_plane_state->dc_state = dc_create_plane_state(dc);
-
-			DRM_DEBUG_DRIVER("Enabling DRM plane: %d on DRM crtc %d\n",
-					plane->base.id, new_plane_crtc->base.id);
-
-			if (!dm_new_plane_state->dc_state) {
+			dc_new_plane_state = dc_create_plane_state(dc);
+			if (!dc_new_plane_state) {
 				ret = -EINVAL;
 				return ret;
 			}
 
+			DRM_DEBUG_DRIVER("Enabling DRM plane: %d on DRM crtc %d\n",
+					plane->base.id, new_plane_crtc->base.id);
+
 			ret = fill_plane_attributes(
 				new_plane_crtc->dev->dev_private,
-				dm_new_plane_state->dc_state,
+				dc_new_plane_state,
 				new_plane_state,
 				new_crtc_state);
-			if (ret)
+			if (ret) {
+				dc_plane_state_release(dc_new_plane_state);
 				return ret;
+			}
 
-
+			/*
+			 * Any atomic check errors that occur after this will
+			 * not need a release. The plane state will be attached
+			 * to the stream, and therefore part of the atomic
+			 * state. It'll be released when the atomic state is
+			 * cleaned.
+			 */
 			if (!dc_add_plane_to_context(
 					dc,
 					dm_new_crtc_state->stream,
-					dm_new_plane_state->dc_state,
+					dc_new_plane_state,
 					dm_state->context)) {
 
+				dc_plane_state_release(dc_new_plane_state);
 				ret = -EINVAL;
 				return ret;
 			}
 
+			dm_new_plane_state->dc_state = dc_new_plane_state;
+
 			/* Tell DC to do a full surface update every time there
 			 * is a plane change. Inefficient, but works for now.
 			 */