drm/amd/display: Correct the plane enumeration order (v2)

The order of planes is given by the order they are enumerated
by kms.
Planes with a higher ID appears above planes with a lower ID.

Currently the planes are enumerated in the wrong order,
putting the nv12 only plane after the two RGBA planes.

This patch corrects the plane enumeration order such that all
the overlay planes are initialized first then the primary planes.

Due to this change in order the dc_add_plane_to_context() shall
receive the planes in reverse order hence this patch reverses
the parsing of planes in DM side itself.

v2: drop local reverse macro for upstream

Signed-off-by: Shirish S <shirish.s@amd.com>
Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@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

@@ -1365,6 +1365,43 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm)
 
 #endif
 
+static int initialize_plane(struct amdgpu_display_manager *dm,
+			     struct amdgpu_mode_info *mode_info,
+			     int plane_id)
+{
+	struct amdgpu_plane *plane;
+	unsigned long possible_crtcs;
+	int ret = 0;
+
+	plane = kzalloc(sizeof(struct amdgpu_plane), GFP_KERNEL);
+	mode_info->planes[plane_id] = plane;
+
+	if (!plane) {
+		DRM_ERROR("KMS: Failed to allocate plane\n");
+		return -ENOMEM;
+	}
+	plane->base.type = mode_info->plane_type[plane_id];
+
+	/*
+	 * HACK: IGT tests expect that each plane can only have one
+	 * one possible CRTC. For now, set one CRTC for each
+	 * plane that is not an underlay, but still allow multiple
+	 * CRTCs for underlay planes.
+	 */
+	possible_crtcs = 1 << plane_id;
+	if (plane_id >= dm->dc->caps.max_streams)
+		possible_crtcs = 0xff;
+
+	ret = amdgpu_dm_plane_init(dm, mode_info->planes[plane_id], possible_crtcs);
+
+	if (ret) {
+		DRM_ERROR("KMS: Failed to initialize plane\n");
+		return ret;
+	}
+
+	return ret;
+}
+
 /* In this architecture, the association
  * connector -> encoder -> crtc
  * id not really requried. The crtc and connector will hold the
@@ -1375,12 +1412,12 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm)
 static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
 {
 	struct amdgpu_display_manager *dm = &adev->dm;
-	uint32_t i;
+	int32_t i;
 	struct amdgpu_dm_connector *aconnector = NULL;
 	struct amdgpu_encoder *aencoder = NULL;
 	struct amdgpu_mode_info *mode_info = &adev->mode_info;
 	uint32_t link_cnt;
-	unsigned long possible_crtcs;
+	int32_t total_overlay_planes, total_primary_planes;
 
 	link_cnt = dm->dc->caps.max_links;
 	if (amdgpu_dm_mode_config_init(dm->adev)) {
@@ -1388,30 +1425,22 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
 		return -1;
 	}
 
-	for (i = 0; i < dm->dc->caps.max_planes; i++) {
-		struct amdgpu_plane *plane;
+	/* Identify the number of planes to be initialized */
+	total_overlay_planes = dm->dc->caps.max_slave_planes;
+	total_primary_planes = dm->dc->caps.max_planes - dm->dc->caps.max_slave_planes;
 
-		plane = kzalloc(sizeof(struct amdgpu_plane), GFP_KERNEL);
-		mode_info->planes[i] = plane;
-
-		if (!plane) {
-			DRM_ERROR("KMS: Failed to allocate plane\n");
+	/* First initialize overlay planes, index starting after primary planes */
+	for (i = (total_overlay_planes - 1); i >= 0; i--) {
+		if (initialize_plane(dm, mode_info, (total_primary_planes + i))) {
+			DRM_ERROR("KMS: Failed to initialize overlay plane\n");
 			goto fail;
 		}
-		plane->base.type = mode_info->plane_type[i];
-
-		/*
-		 * HACK: IGT tests expect that each plane can only have one
-		 * one possible CRTC. For now, set one CRTC for each
-		 * plane that is not an underlay, but still allow multiple
-		 * CRTCs for underlay planes.
-		 */
-		possible_crtcs = 1 << i;
-		if (i >= dm->dc->caps.max_streams)
-			possible_crtcs = 0xff;
+	}
 
-		if (amdgpu_dm_plane_init(dm, mode_info->planes[i], possible_crtcs)) {
-			DRM_ERROR("KMS: Failed to initialize plane\n");
+	/* Initialize primary planes */
+	for (i = (total_primary_planes - 1); i >= 0; i--) {
+		if (initialize_plane(dm, mode_info, i)) {
+			DRM_ERROR("KMS: Failed to initialize primary plane\n");
 			goto fail;
 		}
 	}
@@ -4695,8 +4724,8 @@ static int dm_update_planes_state(struct dc *dc,
 	int ret = 0;
 
 
-	/* Add new planes */
-	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
+	/* Add new planes, in reverse order as DC expectation */
+	for_each_oldnew_plane_in_state_reverse(state, plane, old_plane_state, new_plane_state, i) {
 		new_plane_crtc = new_plane_state->crtc;
 		old_plane_crtc = old_plane_state->crtc;
 		dm_new_plane_state = to_dm_plane_state(new_plane_state);