drm/amd/display: Fallback to SW cursor if SubVP + cursor too big

[Description]
- For SubVP cursor cannot be cached in MALL, therefore
we will switch to SW cursor if the cursor size exceeds
what can fit in the local DCN buffers (64x64x4)
- Returning false / failure for set_cursor_attributes will
fallback to SW cursor
Reviewed-by: NJun Lei <Jun.Lei@amd.com>
Acked-by: NAlex Hung <alex.hung@amd.com>
Signed-off-by: NAlvin Lee <Alvin.Lee2@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_stream.c

@@ -328,6 +328,11 @@ bool dc_stream_set_cursor_attributes(
 	}
 
 	dc = stream->ctx->dc;
+
+	if (attributes->height * attributes->width * 4 > 16384)
+		if (stream->mall_stream_config.type == SUBVP_MAIN)
+			return false;
+
 	stream->cursor_attributes = *attributes;
 
 	dc_z10_restore(dc);