drm/amd/display: Only add stream to freesync when modeset required

This is a follow-up patch to:

Leo (Sunpeng) Li    Cleanup code that enables freesync

We should only add a stream to freesync if a modeset was requested, so
we don't fill the core freesync map with pointless streams.
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

@@ -4132,12 +4132,28 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 	 * are removed from freesync module
 	 */
 	if (adev->dm.freesync_module) {
-		for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 			struct amdgpu_dm_connector *aconnector = NULL;
 			struct dm_connector_state *dm_new_con_state = NULL;
 			struct amdgpu_crtc *acrtc = NULL;
+			bool modeset_needed;
 
 			dm_new_crtc_state = to_dm_crtc_state(new_crtc_state);
+			dm_old_crtc_state = to_dm_crtc_state(old_crtc_state);
+			modeset_needed = modeset_required(
+					new_crtc_state,
+					dm_new_crtc_state->stream,
+					dm_old_crtc_state->stream);
+			/* We add stream to freesync if:
+			 * 1. Said stream is not null, and
+			 * 2. A modeset is requested. This means that the
+			 *    stream was removed previously, and needs to be
+			 *    replaced.
+			 */
+			if (dm_new_crtc_state->stream == NULL ||
+					!modeset_needed)
+				continue;
+
 			acrtc = to_amdgpu_crtc(crtc);
 
 			aconnector =
@@ -4157,14 +4173,12 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 					state, &aconnector->base);
 			dm_new_con_state = to_dm_connector_state(new_con_state);
 
-			if (dm_new_crtc_state->stream) {
 			mod_freesync_set_user_enable(adev->dm.freesync_module,
 						     &dm_new_crtc_state->stream,
 						     1,
 						     &dm_new_con_state->user_enable);
 		}
 	}
-	}
 
 	if (dm_state->context)
 		WARN_ON(!dc_commit_state(dm->dc, dm_state->context));