drm/i915/display: Use drm helper instead of own loop for damage clips

Use existing drm_atomic_helper_damage_merged from generic drm code
instead of implementing own loop to iterate over damage_clips.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220823112920.352563-4-jouni.hogander@intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>

drivers/gpu/drm/i915/display/intel_psr.c

@@ -1722,8 +1722,6 @@ int intel_psr2_sel_fetch_update(struct intel_atomic_state *state,
 					     new_plane_state, i) {
 		struct drm_rect src, damaged_area = { .x1 = 0, .y1 = -1,
 						      .x2 = INT_MAX };
-		struct drm_atomic_helper_damage_iter iter;
-		struct drm_rect clip;
 
 		if (new_plane_state->uapi.crtc != crtc_state->uapi.crtc)
 			continue;
@@ -1771,20 +1769,15 @@ int intel_psr2_sel_fetch_update(struct intel_atomic_state *state,
 		src = drm_plane_state_src(&new_plane_state->uapi);
 		drm_rect_fp_to_int(&src, &src);
 
-		drm_atomic_helper_damage_iter_init(&iter,
-						   &old_plane_state->uapi,
-						   &new_plane_state->uapi);
-		drm_atomic_for_each_plane_damage(&iter, &clip) {
-			if (drm_rect_intersect(&clip, &src))
-				clip_area_update(&damaged_area, &clip,
-						 &crtc_state->pipe_src);
-		}
-
-		if (damaged_area.y1 == -1)
+		if (!drm_atomic_helper_damage_merged(&old_plane_state->uapi,
+						     &new_plane_state->uapi, &damaged_area))
 			continue;
 
 		damaged_area.y1 += new_plane_state->uapi.dst.y1 - src.y1;
 		damaged_area.y2 += new_plane_state->uapi.dst.y1 - src.y1;
+		damaged_area.x1 += new_plane_state->uapi.dst.x1 - src.x1;
+		damaged_area.x2 += new_plane_state->uapi.dst.x1 - src.x1;
+
 		clip_area_update(&pipe_clip, &damaged_area, &crtc_state->pipe_src);
 	}