3 files changed, 20 insertions, 50 deletions

diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index eb13c479e11d..bb1c8402c67d 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -182,10 +182,9 @@ enum qdio_irq_poll_states {
 };
 
 struct qdio_input_q {
-	/* first ACK'ed buffer */
-	int ack_start;
-	/* how many SBALs are acknowledged */
-	int ack_count;
+	/* Batch of SBALs that we processed while polling the queue: */
+	unsigned int batch_start;
+	unsigned int batch_count;
 	/* last time of noticing incoming data */
 	u64 timestamp;
 };
diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 286b044fb027..da95c923d81a 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -110,8 +110,8 @@ static int qstat_show(struct seq_file *m, void *v)
 	seq_printf(m, "nr_used: %d  ftc: %d\n",
 		   atomic_read(&q->nr_buf_used), q->first_to_check);
 	if (q->is_input_q) {
-		seq_printf(m, "ack start: %d  ack count: %d\n",
-			   q->u.in.ack_start, q->u.in.ack_count);
+		seq_printf(m, "batch start: %u  batch count: %u\n",
+			   q->u.in.batch_start, q->u.in.batch_count);
 		seq_printf(m, "DSCI: %x   IRQs disabled: %u\n",
 			   *(u8 *)q->irq_ptr->dsci,
 			   test_bit(QDIO_IRQ_DISABLED,
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index bb137f962c3f..1aa94683d789 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -400,15 +400,15 @@ int debug_get_buf_state(struct qdio_q *q, unsigned int bufnr,
 
 static inline void qdio_stop_polling(struct qdio_q *q)
 {
-	if (!q->u.in.ack_count)
+	if (!q->u.in.batch_count)
 		return;
 
 	qperf_inc(q, stop_polling);
 
 	/* show the card that we are not polling anymore */
-	set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
-		       q->u.in.ack_count);
-	q->u.in.ack_count = 0;
+	set_buf_states(q, q->u.in.batch_start, SLSB_P_INPUT_NOT_INIT,
+		       q->u.in.batch_count);
+	q->u.in.batch_count = 0;
 }
 
 static inline void account_sbals(struct qdio_q *q, unsigned int count)
@@ -448,42 +448,13 @@ static void process_buffer_error(struct qdio_q *q, unsigned int start,
 static inline void inbound_handle_work(struct qdio_q *q, unsigned int start,
 				       int count, bool auto_ack)
 {
-	int new;
+	/* ACK the newest SBAL: */
+	if (!auto_ack)
+		set_buf_state(q, add_buf(start, count - 1), SLSB_P_INPUT_ACK);
 
-	if (auto_ack) {
-		if (!q->u.in.ack_count) {
-			q->u.in.ack_count = count;
-			q->u.in.ack_start = start;
-			return;
-		}
-
-		/* delete the previous ACK's */
-		set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
-			       q->u.in.ack_count);
-		q->u.in.ack_count = count;
-		q->u.in.ack_start = start;
-		return;
-	}
-
-	/*
-	 * ACK the newest buffer. The ACK will be removed in qdio_stop_polling
-	 * or by the next inbound run.
-	 */
-	new = add_buf(start, count - 1);
-	set_buf_state(q, new, SLSB_P_INPUT_ACK);
-
-	/* delete the previous ACKs */
-	if (q->u.in.ack_count)
-		set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
-			       q->u.in.ack_count);
-
-	q->u.in.ack_count = 1;
-	q->u.in.ack_start = new;
-	count--;
-	if (!count)
-		return;
-	/* need to change ALL buffers to get more interrupts */
-	set_buf_states(q, start, SLSB_P_INPUT_NOT_INIT, count);
+	if (!q->u.in.batch_count)
+		q->u.in.batch_start = start;
+	q->u.in.batch_count += count;
 }
 
 static int get_inbound_buffer_frontier(struct qdio_q *q, unsigned int start)
@@ -1453,12 +1424,12 @@ static int handle_inbound(struct qdio_q *q, unsigned int callflags,
 
 	qperf_inc(q, inbound_call);
 
-	/* If any ACKed SBALs are returned to HW, adjust ACK tracking: */
-	overlap = min(count - sub_buf(q->u.in.ack_start, bufnr),
-		      q->u.in.ack_count);
+	/* If any processed SBALs are returned to HW, adjust our tracking: */
+	overlap = min_t(int, count - sub_buf(q->u.in.batch_start, bufnr),
+			     q->u.in.batch_count);
 	if (overlap > 0) {
-		q->u.in.ack_start = add_buf(q->u.in.ack_start, overlap);
-		q->u.in.ack_count -= overlap;
+		q->u.in.batch_start = add_buf(q->u.in.batch_start, overlap);
+		q->u.in.batch_count -= overlap;
 	}
 
 	count = set_buf_states(q, bufnr, SLSB_CU_INPUT_EMPTY, count);