auring_tailptr
arg->dst = auring_tailptr(stage->dst);
mixer->codecarg.dst = auring_tailptr(&mixer->hwbuf);
mixer->codecarg.dst = auring_tailptr(&mixer->hwbuf);
mixer->codecarg.dst = auring_tailptr(&mixer->codecbuf);
codecarg.dst = auring_tailptr(&tmpsrc);
start = auring_tailptr(&mixer->hwbuf);