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s390/qdio: allow to scan all 128 Input SBALs

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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>
This commit is contained in:
Julian Wiedmann 2020-06-17 15:30:14 +02:00 committed by Heiko Carstens
parent 529683d470
commit 2bbf282a5e
1 changed files with 1 additions and 5 deletions
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6
drivers/s390/cio/qdio_main.c
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@ -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;