drm/amd/display: Assume active upper layer owns the HW cursor

[why]
The current logic checks if there's an upper pipe whose viewport
completely covers the current pipe viewport.
This fails in pipe splitting case as you can have layer 1 pipe that
crosses the two layer 0 pipes where it's contained in both, but neither
covers it completely, hence we allow the cursor on both layers.

[How]
Instead of trying to "sum up" rectangles from the higher level pipes
which could leave gaps and would not work generically, we will assume if
there's an upper layer that is active, it will control the HW cursor.
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -3180,24 +3180,18 @@ void dcn10_update_dchub(struct dce_hwseq *hws, struct dchub_init_data *dh_data)
 static bool dcn10_can_pipe_disable_cursor(struct pipe_ctx *pipe_ctx)
 {
 	struct pipe_ctx *test_pipe;
-	const struct rect *r1 = &pipe_ctx->plane_res.scl_data.recout, *r2;
-	int r1_r = r1->x + r1->width, r1_b = r1->y + r1->height, r2_r, r2_b;
+	int cur_layer = pipe_ctx->plane_state->layer_index;
 
 	/**
-	 * Disable the cursor if there's another pipe above this with a
-	 * plane that contains this pipe's viewport to prevent double cursor
-	 * and incorrect scaling artifacts.
+	 * Disable the cursor if there's there's an upper layer active,
+	 * assume it's the one owning the cursor
 	 */
 	for (test_pipe = pipe_ctx->top_pipe; test_pipe;
 	     test_pipe = test_pipe->top_pipe) {
 		if (!test_pipe->plane_state->visible)
 			continue;
 
-		r2 = &test_pipe->plane_res.scl_data.recout;
-		r2_r = r2->x + r2->width;
-		r2_b = r2->y + r2->height;
-
-		if (r1->x >= r2->x && r1->y >= r2->y && r1_r <= r2_r && r1_b <= r2_b)
+		if (test_pipe->plane_state->layer_index < cur_layer)
 			return true;
 	}