From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Wed, 17 Jun 2020 15:30:14 +0200
Subject: s390/qdio: allow to scan all 128 Input SBALs
Git-commit: 2bbf282a5e8e7e6b36586718b484a36117b6b8a0
Patch-mainline: v5.9-rc1
References: jsc#SLE-13690

The comment is inaccurate, qdio_inbound_q_moved() and/or its callers no
longer get confused by a count of 128 completed SBALs.

Scanning all 128 SBALs at once can improve IRQ reduction (as we now
place the ACK at the right spot), and reduce the amount of processing
needed to handle all completed SBALs.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/cio/qdio_main.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index d4c699773070..0c1f186c6291 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -457,11 +457,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q, unsigned int start)
 
 	q->timestamp = get_tod_clock_fast();
 
-	/*
-	 * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
-	 * would return 0.
-	 */
-	count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK);
+	count = atomic_read(&q->nr_buf_used);
 	if (!count)
 		return 0;