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| author | Julian Wiedmann <jwi@linux.ibm.com> | 2019-04-01 10:08:08 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-05-08 15:01:23 +0200 |
| commit | 3060781f2664d34af641247aeac62696405a3fde (patch) | |
| tree | 6dc9b7de3d10a5226862c867801b2aa58059a62f /drivers/s390 | |
| parent | 22e2fe8551f83d43619211623c739e98dfa8ff08 (diff) | |
| download | linux-3060781f2664d34af641247aeac62696405a3fde.tar.bz2 | |
s390/qdio: allow to scan all Output SBALs in one go
Old code restricted the number of inspected SBALs to
QDIO_MAX_BUFFERS_PER_Q - 1, as otherwise the first_to_check and
first_to_kick cursors could overlap. Subsequent code would then assume that
there was no progress on the queue, when in fact _all_ SBALs on the queue
were ready-to-process.
This limitation no longer applies, so allow the queue-scan code to inspect
all SBALs on the queue. Note that qeth requires an additional patch
("s390/qeth: stop/wake TX queues based on their fill level"), to avoid
potential queue stalls when all 128 SBALs are reported as ready-to-process.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/cio/qdio_main.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index cfce255521ac..957c2a8dfc13 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -719,11 +719,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q, unsigned int start) multicast_outbound(q))) qdio_siga_sync_q(q); - /* - * 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; |