dc_pipe_mapping_scratch
struct dc_pipe_mapping_scratch scratch;
memset(&scratch, 0, sizeof(struct dc_pipe_mapping_scratch));
struct dc_pipe_mapping_scratch *scratch,
struct dc_pipe_mapping_scratch *scratch, const struct dc_state *existing_state)
int plane_index, struct dc_pipe_mapping_scratch *scratch, const struct dc_state *existing_state)