diff --git a/drivers/s390/cio/cio_debug.h b/drivers/s390/cio/cio_debug.h
index f88844a..c9bf898 100644
--- a/drivers/s390/cio/cio_debug.h
+++ b/drivers/s390/cio/cio_debug.h
@@ -23,6 +23,8 @@
 static inline void
 CIO_HEX_EVENT(int level, void *data, int length)
 {
+	if (unlikely(!cio_debug_trace_id))
+		return;
 	while (length > 0) {
 		debug_event(cio_debug_trace_id, level, data, length);
 		length -= cio_debug_trace_id->buf_size;