diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 6b340e6e29ac..bd26df85f559 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -214,7 +214,10 @@ again:
 	return 0;
 }
 
-/* returns number of examined buffers and their common state in *state */
+/*
+ * Returns number of examined buffers and their common state in *state.
+ * Requested number of buffers-to-examine must be > 0.
+ */
 static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
 				 unsigned char *state, unsigned int count,
 				 int auto_ack, int merge_pending)
@@ -225,17 +228,23 @@ static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
 	if (is_qebsm(q))
 		return qdio_do_eqbs(q, state, bufnr, count, auto_ack);
 
-	for (i = 0; i < count; i++) {
-		if (!__state) {
-			__state = q->slsb.val[bufnr];
-			if (merge_pending && __state == SLSB_P_OUTPUT_PENDING)
-				__state = SLSB_P_OUTPUT_EMPTY;
-		} else if (merge_pending) {
-			if ((q->slsb.val[bufnr] & __state) != __state)
-				break;
-		} else if (q->slsb.val[bufnr] != __state)
-			break;
+	/* get initial state: */
+	__state = q->slsb.val[bufnr];
+	if (merge_pending && __state == SLSB_P_OUTPUT_PENDING)
+		__state = SLSB_P_OUTPUT_EMPTY;
+
+	for (i = 1; i < count; i++) {
 		bufnr = next_buf(bufnr);
+
+		/* merge PENDING into EMPTY: */
+		if (merge_pending &&
+		    q->slsb.val[bufnr] == SLSB_P_OUTPUT_PENDING &&
+		    __state == SLSB_P_OUTPUT_EMPTY)
+			continue;
+
+		/* stop if next state differs from initial state: */
+		if (q->slsb.val[bufnr] != __state)
+			break;
 	}
 	*state = __state;
 	return i;